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Lambing Time - Summary

Preparation for Lambing

Whilst it is probably erroneous to suggest that one period of the sheep year is any more important than another, there is no doubt that lambing time should be the climax of the year's work. Unfortunately, in many flocks this is not always the case, often because of inadequate preparation and lack of attention to detail throughout the year.
Birth is the most hazardous period in any animal's life. Since the sheep is a seasonal breeder, a large number of births take place over a relatively short time, putting pressure on both the shepherd and the sheep. It is nevertheless the shepherd's responsibility to minimise losses of both lambs and ewes and to ensure that neither are subjected to any unnecessary stress or hazard. Apart from welfare considerations, it makes sound economic sense to rear as many fit and healthy lambs as possible. It is unfortunate that economic pressures mean that shepherds today often have too many ewes to look after.

TRAINING

All young people who are to be given this responsible job should receive some formal training. Even the most experienced shepherds will benefit from occasional refresher courses, such as those organised by the Agri¬cultural Training Board, to update themselves on the latest techniques of their craft. Any who consider such updating to be unnecessary are almost certainly deluding themselves and probably allowing unnecessary suffering and loss amongst their charges as a consequence. There is, for example, no possible excuse for ignorance of the techniques for preventing and treating hypothermia in lambs, which should be in use on every sheep farm in the land, without exception.
Some deaths amongst lambs and ewes at lambing time are inevitable, even in the best managed flocks, but the huge losses of lambs in the national flock are totally unacceptable because the majority of them are avoidable. Figures of 15% average mortality, or 3 to 4 million lamb deaths per year in the UK are largely meaningless, causing only a momentary raising of the eyebrows. However, if from a 500 ewe lowland flock where 900 lambs are born (180%), the 135 lambs which die (15%) were laid nose to tail, they would stretch for about 50 metres and weigh approximately half a tonne. If they were valued at only £40 each at slaughter, this would represent a potential loss of £5,400 in income.
The hope is that this section of the book will assist in reducing losses of both ewes and lambs to a more acceptable level and also reduce the less obvious losses due to non-fatal and sub-clinical disease.

PRE-LAMBING HUSBANDRY

Among the important tasks which have to be carried out in the late pregnancy period, a pre-lambing visit from your veterinary surgeon who specialises in sheep matters should be most beneficial and cost-effective. It is important to attempt to minimise the number of times that ewes are handled at this time, so a discussion regarding which jobs can safely be done at the same time will be helpful, although some compromises will have to be made. For example, in hill flocks, where gatherings are difficult and stressful for ewes, many shepherds delay booster pasteurella and clostri¬dial vaccinations until the ewes are brought down off the tops to lamb in enclosures or parks. This may be only 10 days or a fortnight before lambing is due to begin and therefore somewhat late for the earliest lambers. Most flocks—both hill and lowland - would benefit from being split into early and late lambing groups, based on ram raddle marks, so that vaccinations could be timed more appropriately. This would ensure that the majority of ewes have sufficiently high levels of antibodies in their colostrum to protect their lambs adequately.
Lowland ewes should be in body condition score of 2.5 to 3 at lambing and hill ewes 2 to 2.5. If any are thin at vaccination time, they should be pulled out and fed preferentially. Any underlying reason for the thinness should be investigated (e.g. teeth, liver fluke). It is important not to make any abrupt changes in the diet around lambing time, but ewes which are to go onto fresh spring grass with their lambs immediately after lambing will need a magnesium supplement added to their concentrate ration. Magnesium can be unpalatable and should be added in increasing amount to the mixture during the last week or 10 days of pregnancy. (There is no need to supplement pregnancy rations with magnesium otherwise.) Ewes should have been checked for trace element status (copper, cobalt and selenium) earlier in pregnancy and the ration corrected accordingly. The same applies to the major elements (calcium and phosphorous) and to the vitamins (e.g. vitamins D and E).
Crutching the ewes - removing any dirty or excess wool from around the ewe's rear end and from the udder - is important, so that the newborn lambs can find the udder quickly and easily in the crucial first few hours of life.

The pre-lambing booster vaccinations against the clostridial infections - The Veterinary Book for Sheep Farmers Ewes should be dosed with an anthelmintic shortly after housing to eliminate all parasitic worms - The Veterinary Book for Sheep Farmers

Plate 7.1 (Above) The pre-lambing booster vaccinations against the clostridial infections plus pasteurellosis are crucially important if lambs are to be protected via colostrum.

Plate 7.2 (Right) Ewes should be dosed with an anthelmintic shortly after housing to eliminate all parasitic worms so that they do not contaminate pastures at turn-out with their lambs.

PREPARATION OF THE LAMBING AREA

Immediately before lambing the flock should be split into early, middle and late lambers and these should, wherever possible, be lambed in separate areas of the house or lambing paddock to reduce the risk of the build-up of infectious disease. In outdoor lambing flocks a different area should be used each year wherever practical, since a number of infectious microorganisms and parasites (e.g. Cryptosporidium) may remain infective from one season to another. However, this risk is much less than the risks of the current season, so a favoured sheltered paddock is acceptable if sensible precautions are taken.
Temporary lambing pens built of straw bales have the advantage that they can be burned at the end of the season, thus destroying any infection with them. Individual pens which become infected, by a scouring lamb for example, can also be burned and replaced. It is useful to have pens covered

For outdoor lambing, a favoured paddock close to the steading is acceptable - The Veterinary Book for Sheep Farmers A hospital area for infectious cases - The Veterinary Book for Sheep Farmers

Plate 7.3 For outdoor lambing, a favoured paddock close to the steading is acceptable. It is always best to lamb early, mid and late lambers in separate enclosures where possible.

 

 

 

Plate 7.4 A hospital area for infectious cases should be apart from the main lambing area. Separate boots and overalls should be worn and strict hygiene observed to reduce the spread of infection.

 

or part covered with corrugated sheeting or something similar, to allow lambs shelter from the rain and wind. It is always wise to have a contingency plan, so that if infection does gain the upper hand, ewes yet to lamb can be moved to a fresh area. If there is no option for flocks lambing indoors but to lamb in the same location each season, every attempt should be made to ensure that the area is scrupulously clean at the start of the lambing.
For outdoor lowland lambings, the area chosen should be in a sheltered position and reasonably close to the farm buildings for handiness and  access to water and electricity. Where possible, ewes should be housed at night, since this is so much more convenient for the shepherd and provides protection for both ewes and lambs in bad weather. Only small numbers of ewes should be brought into the lambing area at any one time, since this will make shepherding easier and reduce the risk of mismothering and the build-up of infection.
Young females lambing for the first time should be in a separate area away from the mature ewe flock to protect them from infection and particularly from enzootic abortion of ewes. Keeping them in a separate group also allows them to be fed preferentially, without having to compete with the ewes.

Any purchased ewes should always be lambed apart from the home flock to avoid cross-infection.

Hospital area

Whether the flock is lambing indoors or outdoors, provision should always be made indoors for a hospital area, where infectious cases can be looked after, and also for an intensive care area for lambs with non-infectious conditions such as hypothermia or broken limbs. The latter can be within the lambing area itself, but the hospital area must be distinctly separate. Shepherds should not traipse back and forth between the infectious area and the clean area without washing hands and changing boots and overalls. This may sound overfussy, but sloppy methods on the part of some shepherds are undoubtedly responsible for the spread of infection at lambing time.

Lambing pens

An adequate number of lambing pens should be constructed. As a rough guide 12 pens will be needed per 100 ewes lambing. However, if a flock is synchronised, so that ewes are lambing thick and fast, then 40 pens may be needed per 100 ewes. Teased flocks would come somewhere between these extremes.
Some indoor lambing flocks provide individual pens for every ewe if space is available, and this has a number of advantages. Ewes can be penned before lambing, rather than being moved after the event, and this allows them to settle down, unmolested by the rest of the mob. Providing the pens are lamb-proof, this should mean less mismothering and a better chance of the lambs finding a teat earlier rather than later, especially those born at night when the shepherd may be snatching a little well-earned sleep. Where ewes have been scanned and the number of foetuses is known, single and triplet bearing ewes can be penned opposite each other, so making cross-fostering easier.
For both indoor and outdoor lambing areas, ensure that there is a dry lie for ewes and lambs. Put slaked lime down on indoor earth floors before bedding up with ample straw. Disinfection during lambing is often difficult or impossible and generous bedding is an excellent substitute. In areas where straw is relatively expensive, it is still a very worthwhile investment, as saving even one lamb will pay for a substantial quantity of straw.

Straw bales provide good shelter for lambing pens and can be burned after lambing - The Veterinary Book for Sheep Farmers

Plate 7.5 Straw bales provide good shelter for lambing pens and can be burned after lambing or after infection in the pens. The plate below shows a large airy building for lambing with ample straw bedding. The building is used for different purposes at other times of the year.

 

Straw bales provide good shelter for lambing pens and can be burned after lambing - The Veterinary Book for Sheep Farmers

LAMBING PREPARATION ON HILL FARMS

On hill farms, the flock at lambing time is much more at the mercy of the weather, since few farms are able to lamb the whole flock on sheltered in-bye land. For some, the single carrying ewes have to lamb on the open hill and on others the twin bearing ewes also.
It is therefore not surprising that in bad years lamb losses can be nothing short of catastrophic, with death rates of 40 or 50% not unheard of. Shepherding, in the true sense of the word, is often impossible under extensive conditions, being reduced to disaster limitation. It can be very demoralising for a shepherd to set off at dawn to find lambs frozen in the snow, or a ewe which has died in the process of a difficult lambing. On the most extensive farms, the chances of a shepherd ever coming across a ewe in the act of lambing are slim indeed, let alone coming across one requiring assistance in time to do some good.
Many hill farms bring ewes down off the high ground into large enclosures lower down the hill to lamb. In this way the shepherd has some degree of control. Ewes and lambs in difficulty can be brought down to the farm buildings by tractor and box or by an all-terrain vehicle. Some farms invest in a sheep shed for in-wintering hoggs. The hoggs can be turned out in spring to allow gimmers and the older and thinner ewes to lamb indoors.
On farms which have reclaimed ground from the hill in order to increase the stocking rate and the lambing percentage, some form of shelter must be provided for the twins. As these will be born at a lighter weight, they will be even more vulnerable to chilling, and access to a warming box and, therefore, electricity will be essential. Pens for mothering-up and for fostering-on lambs should also be provided, preferably indoors.
Scanning ewes to determine lamb numbers has proved to be of particular benefit on hill farms where there are a significant number of twin bearing ewes, since after scanning they can remain on the lowground in relative safety for lambing time. The shepherd can then use the time more produc¬tively than previously, when much of the day was spent bringing ewes with pairs down off the hill—a tedious and time-consuming task.

SUPPLIES OF COLOSTRUM

Once a lamb is safely born into the world, the most important factor for its future survival is an early and adequate feed of colostrum. For one reason or another, some ewes may not have adequate supplies for their lambs. Other lambs may be orphaned, weak or sick and may require supplementary feeds of colostrum. Collection of colostrum from ewes can often be disappointing and it is difficult to judge how much to take from a ewe to leave her with sufficient for her own offspring. Also, supplies must be available right at the start of lambing, and therefore it is essential to collect and store some ewe colostrum from the previous season or to make alternative provisions. The role of colostrum is discussed in detail in Chapter 8.

Goat colostrum and CAE

Goat colostrum is often for sale and is a good substitute for ewe colostrum. However, it it most important to establish that the goat herd is free from caprine arthritis encephalitis (CAE). The virus which causes this disease is closely related to—and cannot be distinguished from—the one responsible for maedi-visna (M-V) in sheep. The virus is shed in goat's milk by which it may be transferred to lambs, which would then react positively to the maedi-visna blood test in later life. This would obviously be highly undesirable in M-V accredited flocks. Also, it is possible for the virus to cause actual clinical illness in lambs, and although this has not been seen in the UK, cases have been reported in New Zealand. A significant proportion of goat herds are known to be infected, but only relatively few are regularly tested, so beware.

Cow colostrum and the anti-ovine factor

Cow colostrum is an acceptable substitute for the ewe product and has the advantage that it can be collected in large quantities for storage in the deep freeze in small quantities of up to 250 ml. A small proportion of cows have an anti-sheep or anti-ovine factor in their colostrum, which leads

Lambing enclosure on a hill farm and individual pens for problem cases in inaccessible areas - The Veterinary Book for Sheep Farmers

Plate 7.6 Lambing enclosure on a hill farm (above left) and individual pens for problem cases in inaccessible areas (above right). Shelter must be available for twin bearing hill ewes and gimmers.

'Blackie' gimmers brought down to riverside parks to lamb - The Veterinary Book for Sheep Farmers

Plate 7.7 'Blackie' gimmers brought down to riverside parks to lamb. Access to areas of open woodland provides vital shelter for ewes lambing on the high, exposed ground.

to the destruction of the red blood cells of any lambs which drink it. This produces a profound anaemia which is usually fatal unless treated early by blood transfusion. Affected lambs initially become very thirsty and some may eat soil. They soon lose their appetite, grow very weak, collapse and die, usually within a day of the onset of illness. The ears and inside of the mouth appear very pale due to the anaemia. If any such cases occur, do not feed any more of that particular cow's colostrum and destroy any that remains, or feed it to calves. Each pot of stored colostrum must be identified with the cow's name or ear number, as well as the date it was frozen. Where cow colostrum is being relied upon, it is also essential to have supplies from at least two or three cows in case a lamb anaemia problem occurs. Samples of colostrum can be tested in the laboratory to give an estimate of the likelihood of anaemia. This condition is relatively uncommon and the value of cow colostrum to lambs needing it far outweighs the small risk. Pooling colostrum from several cows reduces the risk.

Vaccinating cows against the clostridial diseases of sheep Cow colostrum is even more valuable to lambs if it contains antibodies against the clostridial diseases of sheep. This can be arranged by vacci¬nating the cow with 10 ml of a '7 in 1' type clostridial vaccine on three occasions—at three months, one month and a fortnight before calving. Colostrum should be collected from the first two milkings after calving. As colostrum may be needed for premature lambs some time before the onset of the main lambing, suitable cows should be identified and vaccinated for the first time at least four months before lambing. As colostrum freezes satisfactorily, it can of course be collected at any convenient time.

A selection of items needed at lambing time arranged on top of a lamb warming box - The Veterinary Book for Sheep Farmers

Plate 7.8 A selection of items needed at lambing time arranged on top of a lamb warming box.

Colostrum substitutes

A number of live colostrum replacers or substitutes are now on the market, but it is too early to make any recommendations.

The Lambing Process

Pregnancy lasts for approximately five months in the ewe. The majority of lambings occur between days 146 to 148 inclusive, but even in a pure-bred flock, normal lambings will occur between days 140 and 150. Single lambs are generally carried longer than twins or triplets, which tend to be born somewhat prematurely.
It is the lambs which decide when they will be born, rather than the ewe deciding that it is time to deliver her lambs. The whole lambing process is controlled by a complex series of hormonal changes triggered off by the foetal lambs responding to 'stress'.

INITIATION OF THE BIRTH PROCESS

At the end of pregnancy things are getting very cramped in the uterus, with a large foetus (or foetuses), full-grown placenta (afterbirth) and a large accumulation of fluids which bathe and protect the lamb. The foetal lamb receives its oxygen and nutrients from the ewe's blood supply via the placenta and rids itself of waste materials by the reverse route. In the final stages of pregnancy these processes become critical, since the ewe finds it increasingly difficult to maintain the lambs adequately as their demands increase daily. These 'stresses' stimulate the lamb to produce an increasing quantity of a steroid hormone called cortisol, which finds its way into the ewe's bloodstream and is responsible for the initiation of the birth process.

Hormonal changes

All throughout pregnancy it is important that the uterus—which is a large muscular sac—does not contract, since this would jeopardise the life of the lambs. Therefore, the 'buttons' (placentomes) on the placenta secrete the hormone progesterone, which very effectively prevents this happening. Before birth can proceed, the levels of this hormone have to be substantially reduced to allow the uterus to contract and expel the lambs into the world. The cortisol secreted by the lambs causes progesterone to be converted to another hormone called oestrogen, to which it is closely related, but which has very different effects. As progesterone levels fall and oestrogen levels
rise, this has the effect of allowing yet another hormone—prostaglandin F2 alpha (PGF2alpha)— to act on the uterus, causing it to contract and thus beginning the lambing process.

Signs of impending lambing

The hormonal changes going on inside the ewe can be detected by the shepherd in a number of ways. As lambing approaches, the udder gradually develops and fills up with colostrum. This can be seen most easily when ewes are feeding at the trough and particularly in housed ewes which are shorn. This feature is extremely variable and whilst udder development is a reliable sign that lambing is relatively imminent, a lack of udder development does not necessarily mean that lambing is a long way off. Some ewes lamb with virtually no udder development, whilst others may have a well-developed udder for a week or more before they lamb. This depends to some extent on the feeding of the flock.
As lambing time approaches, ewes generally take more and more interest in newborn lambs and may attempt to mother and 'steal' them. This behaviour is due to the fact that the fluids spilt at lambing become very attractive to any imminent ewe.
When contractions of the uterus begin, they do so gradually and ewes will tend to isolate themselves from the rest of the mob and may refuse their concentrate rations. As contractions increase in both strength and frequency, they make the ewes uncomfortable, so that they become very restless. They may scratch and scrape around the chosen 'nesting' spot and get up and down frequently, often stretching out their necks and making nibbling and licking movements.

LABOUR

Meanwhile, inside the ewe, another hormone called relaxin has been at work, softening up the tough tissues which make up the cervix (the neck of the womb) so that it can be stretched to accommodate the passage of the lamb. The ligaments which hold together the bones which form the pelvis, through which the lamb must pass, also soften up, making this rigid ring of bone more flexible. The strong contractions of the uterus force the fluid-filled sacs surrounding the foetus up against the cervix, which then gradually yields and begins to open up. Within a few hours the cervix becomes fully relaxed and open and the lamb itself is pushed into the birth canal.
Up to this stage the ewe has taken a passive role in the process, having herself no conscious control over the muscles which contract the uterus. However, once the head of the lamb (in a normal forward presentation) engages in the pelvic region of the birth canal, this stimulates the ewe to hasten the process further. This she does by 'straining' or 'pushing'—that is, by contracting the muscles of her abdomen—so significantly increasing the pressure on the lamb. Eventually the shepherd will see the 'waterbag' appearing at the now swollen vulva, or, if the waterbag has already burst, perhaps the foot or nose of the lamb poking out. A few more powerful contractions of the abdominal muscles are now necessary to finally expel the lamb, since the uterine contractions become less potent as the lamb passes out of the uterus, through the cervix and into the vagina.

A Clun Forest ewe giving birth onto clean straw bedding - The Veterinary Book for Sheep Farmers

Plate 7.11 A Clun Forest ewe giving birth onto clean straw bedding (left), and the lamb taking its first feed of colostrum within five minutes of birth (below).

lamb taking its first feed of colostrum within five minutes of birth - The Veterinary Book for Sheep Farmers

Once the lamb is expelled and the umbilical cord is finally ruptured, the lamb must immediately take on an independent existence. Rupturing of the cord, release from the restricting confines of the uterus, sudden exposure to the considerable drop in temperature of the outside air and hopefully the nuzzling and licking of the ewe, all stimulate the newborn lamb to take its first vital breaths.

'Cleansing'

The birth of the lambs is not the end of the lambing process, however, since the ewe must also expel what remains of the placentae or afterbirths.  This is often referred to as 'cleansing' or 'cleaning'. This may follow very shortly after the lambs are born or even at the same time, but when lambs are bom slightly prematurely, as most twins and triplets are, it may be some hours before the afterbirths are voided. Not until this happens is lambing complete. If the lambs get up and suck vigorously, this not only stimulates milk let-down, but also encourages further contractions of the uterus which help to void the afterbirth (both processes are stimulated by the same hormone, oxytocin). The uterine contractions also stem any bleeding from the numerous small blood vessels which are ruptured during the birth process. Eventually the cervix closes up again to prevent infection entering the uterus.
It is most important to appreciate that the lambing process has evolved over many thousands of years and, whilst it occasionally goes wrong, it will proceed normally and without incident for the majority of ewes. Ewes will vary in the time taken to complete lambing. For example, first-time lambers may take considerably longer than older ewes. However, the hormonal changes which control lambing coordinate the process in such a way as to ensure the highest survival rate for the lambs.

ADAPTING TO LIFE OUTSIDE THE WOMB

Consider the changes a lamb must adapt to within a very short period of being thrust into an often hostile world. The foetal lamb's lungs contain fluid, but as soon as it is bom it must get rid of these sticky fluids so that it is capable of breathing air. Its blood supply must begin to circulate through its lungs to capture the oxygen. In the uterus it receives all its nutrients from the ewe and is insulated from heat loss by the fluids which surround it, but at birth it must generate its own heat from what energy reserves it has acquired from the ewe during late pregnancy, principally in the form of brown fat.
The lamb must also change from being a foetus of leisure to a vigorous, teat-seeking lamb, able to keep up with its mother in wind, hail, rain or snow. When it sucks colostrum for the first time, its gut must be able to cope with the digestion of a complex food. Its kidneys must also be capable of excreting waste materials and of maintaining the body's fluid balance, and the liver must function in a multitude of ways.
All these organs and systems must be sufficiently mature in order to function satisfactorily and the hormonal influences of the last few days and hours before and during birth are crucially important to the lamb. The corticosteroid hormones which start off the lambing process are also involved in the final stages of maturation of all the lamb's organ systems mentioned above. For example, for the proper functioning of the lungs, a substance called surfactant must be secreted into the lung substance to enable them to inflate and thereby allow the lamb to breathe. If surfactant is not present, then the lungs will remain collapsed and the lamb will perish. The same hormones also control the supply of energy (glycogen) to the newborn lamb, by mobilising carbohydrate from brown fat. This process is essential to its survival in the crucial period before it sucks colostrum. Colostrum then takes over as the sole energy source, since the lamb's own reserves rapidly run out.
Any unwarrented interference with the smooth functioning of the birth process will therefore jeopardise the lamb's chances of survival. This particularly includes pulling lambs out of ewes before they are ready to be bom. This is an instinct in many shepherds which should be strongly resisted, since it is undoubtedly responsible for the death of some lambs.

THE EWE-LAMB BOND

An important feature of early life for the lamb is the relationship it has with its mother. This ewe-lamb bond needs to be manifest immediately the lamb is born, but in fact is established before and during the birth process. The hormones circulating immediately before birth (particularly oestrogen), together with the stimulus the ewe receives during birth, when the lamb is in the birth canal, stimulate strong maternal instincts in the ewe, so that she protects her lamb and licks it dry. In doing so she identifies the unique smell of her own offspring in the foetal fluids which soak it at birth. If this bond is not established quickly after birth, then the chances of its happening fade rapidly by the hour. In licking the lamb, the ewe not only forms a bond with her offspring, but also stimulates it to breathe, to get up and follow her and to bleat. This in turn reinforces the maternal bond and increases the lamb's chances of getting to the teat to take colostrum early, which is so vital to its survival.

Scottish Blackface lamb newly born on a bitterly cold April afternoon at 1,000 feet above sea level - The Veterinary Book for Sheep Farmers Scottish Blackface lamb newly born on a bitterly cold April afternoon at 1,000 feet above sea level - The Veterinary Book for Sheep Farmers

Plate 7.12 Scottish Blackface lamb newly born on a bitterly cold April afternoon at 1,000 feet above sea level. Its survival is totally dependent upon an immediate and close bond with its mother, who must lick it dry and allow it to suck colostrum or it will quickly perish.

SUPERVISION OF THE FLOCK AT LAMBING

Whilst the role of the shepherd at lambing time is a crucial one, it should be remembered that the final outcome will have been largely determined by the management of the flock throughout the year. Indeed, a detailed study of a large lambing flock in Scotland, carried out by the workers at the Moredun Research Institute, indicated that more than two-thirds of the lamb losses occurring at or immediately after lambing were attributable to factors determined before birth. For example, the viability of lambs is strongly influenced by their birth weight, which is largely determined by the size of the placenta, which in turn depends upon how the ewe is fed during the first three months of pregnancy. In a well-managed flock, therefore, the shepherd's job at lambing is almost always going to be easier than in a poorly managed flock. However, all the good work put into the flock throughout the year can be undone by poor shepherding at lambing time.

Welfare at lambing

Whilst the profitability of a flock will depend to a large extent upon the number of lambs reared and therefore upon the number of lambs born and kept alive, this should not be the only consideration at lambing. The welfare of the animals—both ewes and lambs—should always come first. There is no place in the lambing paddock for callous or uncaring individuals. Inexperienced staff should be closely supervised by skilled shepherds at all times. Sheep fanners should provide their shepherds with every reasonable facility to make the job easier and should not expect them to cope with too many lambing ewes, as this will inevitably result in stress and suffering for both sheep and shepherd.
It is not possible to put a figure on the number of ewes one person can look after, as this will vary considerably, depending not only upon the capabilities of the individual, but also upon the circumstances of the flock. Long, spread-out lambings should be avoided, since ewes lambing at the end frequently get less than adequate supervision. Shepherds become fatigued, especially when they have to work long hours with relatively little happening in the lambing area, but much to do elsewhere.
It is a salutary experience to record a lambing in detail and in total honesty, recording all lamb and ewe losses and, wherever possible, getting an accurate diagnosis of all deaths and of any disease outbreaks. It will become apparent from such a survey just where and why problems are occurring, how well or badly the flock is being managed and how well the shepherds are coping with the number of ewes allocated to them. Without accurate records of this type it is not possible to make objective judgements, but merely to gain impressions which may be completely erroneous.
In intensive lowground flocks the level of supervision will, to some extent at least, be dictated by the type of organisation at lambing—for example, on whether or not the flock is housed and on the lambing percentage expected.
Increasing the intensity of stocking, either in-house or in the lambing paddock, will increase the risk of mismothering and the spread of infection and this will necessitate a higher level of shepherding. Extra labour will almost always be required, whether it be skilled, semi-skilled, or simply extra hands to fetch and carry. On the hill the level of shepherding will again be determined by whether or not the ewes (or a proportion of them) are brought down off the hill to lamb in enclosures, fields or a sheep shed.
Maximum supervision with minimum interference The philosophy at lambing should be one of maximum supervision with the minimum of interference. If the ewes have been well looked after, there should be few problems with difficult lambings. If shepherds have to assist a high proportion of ewes—for example, more than about one in 15 or 20—then either they are interfering unnecessarily or there is some other fault in the management or breeding of the flock. Knowing when to interfere is a difficult decision and comes only with training and experience.
It is useful to identify ewes which give problems at lambing and to make a decision on whether to retain such animals and their female progeny for future breeding. Flockmasters in various parts of the world have attempted—often with a degree of success—to breed so-called 'easy care' flocks, which are left completely unattended at lambing time to fend for themselves. This they have done by ruthlessly culling any ewe which has given any trouble of whatever kind at lambing time, whether or not it was the ewe's 'fault'. By so doing it has been possible to reduce the proportion of ewes with lambing problems to a very low level, for example, to around 1 or 2 per cent in some flocks. Whilst there are obviously considerable welfare implications in flocks which are left completely to their own devices, there are, nevertheless, lessons to be learned from such rigorous culling methods.
The lambing shed, paddock or enclosure should be a relatively peaceful place, with the minimum of noise and clamour. A 'softly, softly' approach is desirable, since the less stressed the flock is, the fewer should be the problems. Ewes should preferably be allowed to settle down in the area where they are to lamb and not be shifted from pillar to post. If they are stressed in late pregnancy, ewes may lamb prematurely—so called 'disruption lambings'—and lamb survival may be seriously compromised as a consequence.

Examining and Assisting Ewes at Lambing

There is an important difference between examining a ewe thought to be in trouble and assisting her to lamb. An examination is a necessary prelimi¬nary before deciding what to do and may reveal that nothing is apparently amiss, in which case the ewe should be left to get on with lambing in her own good time, but should be observed at frequent intervals of say half an hour. Ewes should not be internally examined repeatedly when lambing is thought to be progressing normally. It is also entirely wrong to pull a lamb away from a ewe before it is ready to be born. A number of shepherds not only do this, but also delve inside and bring away any other lambs which may be present, either to save them the bother of observing the ewe further, or because they feel that by getting it over and done with the lambs will be safe and sound. This is poor shepherding.
A ewe should only be assisted with her lambing if an examination suggests that she is unlikely to lamb successfully on her own, or that by leaving her to do so may jeopardise the life of the lambs. A number of situations call for examination of a lambing ewe, of which the following are some of the most important:

  • The ewe is wandering about with a wet or blood-stained rear end, but there is no sign of a lamb. This may mean that the ewe has aborted, given birth to a dead lamb or given birth to a healthy lamb which she has abandoned or which has been 'stolen' by another ewe. Check the approximate lambing date from the ram raddle mark.
  • The ewe has been straining her abdominal muscles for an hour or more but there is no sign of a lamb appearing at the vulva.
  • The ewe has been straining for some time, with part of the lamb visible at the vulva, but is making no headway.
  • Part of a lamb is visible at the vulva, but the ewe has given up straining and is wandering about unconcerned, or lying away on her own.
  • The ewe is straining, the waterbag has burst (wet behind) but no progress has been made for some time.
  • The lamb is obviously being born in an abnormal position—for example, tail first, or head first but without one or both forelegs.
  • A ewe which has prolapsed the vagina and been stitched up or had a retainer and truss fitted is showing signs of being about to lamb.
  • A ewe known to be carrying multiple lambs (i.e. scanned) has apparently finished lambing but has not produced the expected number of lambs. (NB: scanning is not foolproof)
  • A ewe has been restless and uneasy for an excessively long period, but has not yet begun to strain, or does so only intermittently. Afterbirth may be seen at the vulva but no sign of a lamb.

It is important to keep an extra careful watch on any ewes which have been unwell during pregnancy. They are best penned up in a separate area for ease of observation.

THE EXAMINATION

Wherever possible, it is highly desirable that any ewe to be examined is brought indoors. Whilst some may need no assistance to lamb, others undoubtedly will and it is both easier to practice good hygiene indoors and much more convenient. Also, should things prove awkward, assistance is at

Ballotment. By gently pushing the clenched fist into the lower abdomen, it is sometimes possible to determine whether the lamb is alive - The Veterinary Book for Sheep Farmers

 

 

Plate 7.13 Ballotment. By gently pushing the clenched fist into the lower abdomen, it is sometimes possible to determine whether the lamb is alive.

Supporting a ewe for vaginal examination single- handed - The Veterinary Book for Sheep Farmers

 

 

 

 

Plate 7.14 Supporting a ewe for vaginal examination single- handed. Ewes must not be held in this position for too long.

hand—for example, to look after lambs which have had a difficult birth. Everything which could be needed to assist a ewe to lamb should be immediately to hand before starting any examination.
Before any internal examination, gently tip the ewe so she is sitting up on her hind end. Examine the udder with clean hands, remembering that absence of development does not necessarily mean the ewe is some way off lambing. Check for any signs of mastitis, but do not draw off any milk at this stage even if you suspect infection, since you will contaminate your hands. In any case never strip any mastitic secretion onto the floor of the lambing area as this will effectively contaminate it for other ewes.
While the ewe is sitting upright, clench a fist and press it gently but firmly against the abdomen just above the udder. By keeping contact with the skin and moving the fist in and out it should be possible to bounce the knuckles gently against the lamb or lambs. If the fist is pushed firmly against a lamb and held there it may also be possible to feel movement, confirming that the lamb is alive and kicking. This technique, called ballotment, is also useful for detecting the presence of a twin or triplet after the birth of one lamb, without the need for an internal examination (see Plate 7.13).
Choose a clean, well-strawed area and lay the ewe gently on whichever side will be most comfortable for you to examine her. Except for the most simple examination it is always easier to lift the ewe up on to straw bales to a comfortable working height. Another bale covered with a paper sack can be used as a table for any equipment required. An assistant should hold her down whilst you clean up her rear end with copious amounts of soapy water. Paper towels are useful to mop up excess moisture.
Next, thoroughly wash your hands and arms using clean and preferably warm water. The importance of cleanliness before carrying out even the most cursory examination cannot be overemphasised. Even with the greatest care you will inevitably introduce some infection, but careful washing will minimise the risks. Make sure that fingernails are clean and short and if you have hands like shovels, ingrained with dirt, ask someone else to carry out the examination! Use only the mildest antiseptic solutions for washing, at suitably low dilutions, remembering that the delicate tissues lining the vagina are very easily damaged by inappropriate chemicals.
For preliminary examinations and for very simple manipulations the ewe can be restrained on her side as described, but in many cases it is very helpful to have an assistant hold up the ewe's hind end by using soft rope or, better still, a home-made device of narrow webbing, which is slung over the shoulders and attached above the ewe's hocks. The ewe's fore legs are best tied together so that she cannot make a bid to escape. The reason for using this technique is that many manipulations will require the repositioning of the lamb or lambs and to do this they must be returned to the uterus, often against the vigorous straining of the ewe. Therefore, a little help from Sir Isaac Newton (gravity!) is extremely useful. It is much easier to work standing up, easier to keep the area clean and to reach for things. When lubricant is applied, it also runs in the right direction.
However, the weight of the uterus and its contents, plus that of the full rumen, will be pressing on the ewe's diaphragm, which will make it difficult for her to breathe. There is also the risk of regurgitation of rumen contents, which could choke her. She must therefore be made as comfortable as possible and not be upended for too long. Hopefully, most manipulations should be completed in a short time.

LUBRICATION

It is essential to use liberal amounts of a suitable lubricant. Even the smallest lambs are too big to pass through the birth canal without adequate lubrication and for large lambs the journey is impossible without it. The tissues lining the birth canal—the mucous membranes—are very delicate and bruise and tear easily if not handled with the greatest respect. Apart from the discomfort to the ewe, such damage may cause haemorrhage

Scrupulous cleanliness is essential before lambing a ewe - The Veterinary Book for Sheep Farmers

Plate 7.15 Scrupulous cleanliness is essential before lambing a ewe.

Where washing facilities are not available, an antibiotic (cow intramammary preparation) can be smeared onto the hands - The Veterinary Book for Sheep Farmers

Plate 7.16 Where washing facilities are not available, an antibiotic (cow intramammary preparation) can be smeared onto the hands. The shepherd's hands should be washed at the first opportunity. (Beware of penicillin allergy.)

or infection, which can lead to her death. The ewe provides her own lubri¬cants, of course, but these fluids may already have been lost if she has been attempting to lamb for some time. Use only a suitably bland, non-irritant product, several of which are on the market. Many of the gels are made more slippery by the addition of clean water. It is sometimes difficult to get sufficient lubricant past a tightly fitting, dried-out lamb which is stuck in the pelvis. This is helped by using a short piece of stout rubber tubing with a smoothed off end, attached to a syringe or to a squeezy bottle with a suitable nozzle for 'injecting' the lubricant around the stuck lamb. Alternatively, the hard margarine method often gives excellent results (see below).
Insert one hand very carefully and try to assess the situation. Move around slowly and gently inside the ewe and keep adding lubricant so that your hand glides over the tissues. Do not keep pulling your hand in and out of the ewe and do not change hands without washing again, since the one you are not using will be heavily contaminated.
It will be obvious immediately if a lamb is already in the birth passage. It is important to know if the lamb is dead or alive. A live lamb will assist to some extent with its own birth, whereas a dead lamb is almost always more difficult for the ewe to deliver. If a lamb has been dead for any length of time it will inevitably have dried up to a greater or lesser degree and if any infection is present the lamb may also be swollen. This combination means that the ewe will inevitably require assistance (see below).
It is not always as easy as it might be imagined to decide if a lamb is alive. If the lamb moves, then obviously there is no difficulty, but some may lie perfectly still for long periods, particularly if the ewe has already been in labour for some time. Slipping a finger into the mouth should elicit a sucking response. Failing that, pinching the septum between the nostrils or the skin between the cleats of the hoof should stimulate a withdrawal response. If you are able to feel the chest wall, it may be possible to feel the heart beating. If you cannot be sure, always assume that the lamb is alive.

PRESENTATION OF THE LAMBS

Most lambs are born with both forelegs coming first and partially extended, with the head pointing forwards and resting on the limbs as shown in Figure 7.1. This position causes the least problems at lambing and is considered the normal presentation. Any other position may lead to lambing difficulties, although not inevitably. Ewes can deliver lambs coming backwards (hind limbs first) or with only one foreleg and a head, for example, but most other positions are impossible without assistance.
It is crucial to discover not only which way the lamb is presented, but also whether more than one lamb is present in the birth canal. This is frequently confusing, especially for inexperienced shepherds, but important, since extracting two lambs at once is impossible and the attempt is likely to damage the ewe and both lambs. The secret is to keep the hand in contact

Normal presentation of a single lamb - The Veterinary Book for Sheep Farmers

Figure 7. 1 Normal presentation of a single lamb. Note how the fore legs are still partially flexed at the elbow.

with the lamb during the examination and to start with a limb—fore or hind— and follow it up, round and down the equal and opposite limb. If necessary loop a lambing rope around the legs identified as belonging to one lamb before starting to sort out any other legs present. In most cases where there are more than two legs present in the birth canal, it will mean that more than one lamb is making a bid for freedom at the same time; however, if only two legs are present they may not necessarily belong to the same lamb. If the 'keeping in contact' method is used, it should be possible to sort out the puzzle.
It is essential to be able to distinguish fore from hind limbs. Where it is only possible to feel the extremities of the limbs, start at the feet and note the direction in which the joints move. In the fore limb, both the fetlock and the knee joints move in the same direction. In the hind limb, the fetlock and hock joints move in opposite directions. Additionally, the shoulder blade can be felt in the fore limb, if this can be reached.

MANIPULATING LAMBS BEFORE DELIVERY

It is important to appreciate that, however small the lamb and roomy the ewe, and however slim, delicate and skilled the shepherd's hands might be, there is never sufficient room to correct the position of a lamb lying in the birth canal. The pelvis is a ring of bone through which the birth canal passes, and although the ligaments between the individual joints of the pelvis become more flexible at lambing, it nevertheless remains a relatively rigid structure. If a hand is introduced into the vagina, even when no lamb is present, it is obvious how little room there is for manoeuvre. Therefore, lambs must always be returned to the uterus before any corrections are attempted.
Great care must be taken in returning lambs to the uterus. Whilst it may appear reasonable to assume that if the lamb has come out of the uterus through the cervix, then it should go back, this is not always the case. For example, if a lamb has been stuck in the birth canal for some time, it may have swelled up and the cervix may have begun to close up again, so gripping the lamb tightly. Again, the secret is to lubricate well and to push the lamb back slowly and steadily. Remember that the uterus is a thin, muscular bag at this time and can very easily be punctured by a lamb's foot or a finger, especially if the waterbag has burst and the protective fluids have been lost. Once back in the uterus there will be more room for manoeuvre—but little enough—especially if more than one lamb is present.
If examination reveals that the lambs are in the uterus, it has to be decided if the birth canal is sufficiently dilated and relaxed to allow the passage of the lambs. The vagina itself is a soft, muscular, elastic tube, whereas the cervix is shorter and is composed of much thicker and less pliable tissue, which relaxes and opens up for only a short period to allow the lambs to be born. If the hand is inserted, then depending upon the length of the vagina (which varies considerably from ewe to ewe), the cervix will be located roughly a small hand's length inside the ewe. If the cervix is fully open, then it will be difficult to detect it at all and a reasonably sized, well-lubricated hand will be able to pass straight through into the uterus unhindered. In this relaxed state it is permissible to withdraw lambs which have been repositioned or untangled from each other, if this is thought necessary.
However, if the cervix can be felt as a tight ring of tissue through which it is only just possible to insert a small hand, or indeed only two or three fingers, then the ewe is not ready to lamb. On no account should any attempt be made to deliver lambs when the birth canal is only partially dilated. To do so is likely to cause serious damage to the ewe in the form of tearing and haemorrhage and may also injure and compromise the lambs (see below). In these cases it is best to leave the ewe for a half to one hour and then re-examine her. If the cervix is no further open, then it is worth while settling the ewe in a comfortable lying position, inserting a well-lubricated hand and gently working the fingers and knuckles around inside the rim of the cervix in the hope that it might relax and open up. This takes time and patience but is rewarded in a proportion of cases.
It is possible that some affected ewes are hypocalcaemic (calcium de¬ficient), but not so as to produce any clinical symptoms. Therefore it is some¬times helpful to inject 100 ml of calcium borogluconate solution (20%) under the skin. This will do no harm and may assist in some cases. Muscle relaxants (which can only be prescribed by your veterinary surgeon) appear to be largely ineffective in this condition. In most cases the ewe simply needs time and perhaps a little assistance, before the cervix finally yields to allow the deliv¬ery of the lambs.

RINGWOMB

This is a relatively rare condition and can be thought of as an extreme form of failure of the cervix to dilate, as described above. True ring womb cases do not respond to any medical treatment or to gentle manipulation. Affected ewes may have been attempting to lamb for many hours. They are often very restless, getting up and down frequently, and are unable to settle. Occasionally, some afterbirth may be seen trailing from the vulva and on examination, the cervix will be felt as a tight, hard ring through which only one, or possibly two, fingers can be inserted. There are many theories as to the reason for this condition—for example, that it is more common in ewes which have previously prolapsed the vagina—but since none of the theories has been tested, the cause remains unknown.
If an affected ewe does not respond to treatment or manipulation, then any hope of removing the lambs by the normal route should be abandoned and your veterinary surgeon given the case to deal with. Providing the ewe is in reasonable condition and the lambs are alive, then caesarean section is often the best option. Hopefully this will yield live lambs and a ewe capable of looking after them. If, however, the ewe has been trying to lamb for a long time and the placentae have become separated, the lambs may be dead, in which case caesarean section is not usually an option and the ewe may have to be slaughtered. Ewes affected with ring womb which are successfully caesared should be permanently marked and culled from the flock.

THE USE OF LAMBING ROPES, AIDS AND OTHER DEVICES

These can be most helpful in a number of situations, but care must be taken in their use. It is possible to secure a firmer hold using such items than it is with a well-lubricated hand. However, it is always more difficult to judge when too much traction is being applied than it is with the hand alone. Never pull on ropes without guiding the lamb with the other hand inside the ewe; otherwise grave damage may be done to the uterus and birth canal—for instance, by a foot puncturing the uterus. It is always safer if the same person does the pulling and the guiding—an assistant holding the ewe.
Ropes can be used merely as landmarks to identify the limbs or the head of a lamb—for example, when trying to disentangle twins (different coloured ropes are sometimes useful for this purpose). They can also be extremely useful in holding or guiding part of a lamb during the correction of its position in the uterus. The most common example is when a head keeps flopping back into the uterus as a lamb is drawn forward into the birth canal.
The attachment of ropes must be done correctly so as not to damage the lamb. They are usually provided with a ready made loop in the end so a noose can easily be made. When attaching a rope to a limb, the loop must always go above the fetlock joint and not down around the pastern, since traction at this lower point may damage the joint or pull the hoof off, in which case the lamb will have to be destroyed. When roping the head, the noose should be applied behind the ears and through the mouth, not around the neck, which could obviously strangle the lamb. When pulling on the head, the rope will tend to tilt the head upwards somewhat and also force open the mouth, which can cause some difficulty. Great care must be taken not to dislocate or fracture the fragile jaws of the lamb.
Rubber ropes are kinder to the lamb and have strategically placed 'knots' to prevent the noose from tightening too much. The amount of pull is also modified to some extent by the elasticity of the rubber. They are also easier to clean and sterilise. Ropes and lambing aids should be washed very thoroughly immediately after use and boiled for 20 minutes before being used again. They are best stored in a mild antiseptic solution, such as Milton, never in a strong disinfectant solution. Keep a plentiful supply so that there are always some sterilised and ready for use. Used ropes left lying around and then used unsterilised on another ewe are an excellent way of spreading infection, not only to the ewe but also to the lambs, even before they are born.

BIRTH TRAUMA

When delivering lambs, with or without the use of lambing ropes, please remember how fragile foetal lambs are and therefore how easily they may be damaged. A very significant proportion of lambs are injured during the birth process, as is demonstrated by detailed post-mortem examination. Even lambs born naturally, without any human intervention whatsoever, may be injured by the crushing pressures bearing down on them during the birth process. Any additional force applied by hand will increase the risk of injury very significantly. Many more lambs die either directly or indirectly through birth trauma than is ever appreciated.
Returning lambs from the birth canal to the uterus and correcting any abnormal posture is most easily done when the ewe is not straining. Upending the ewe is helpful, since her pressing is less effective in this position. When pulling the lamb away, it is best to wait for the ewe to strain unless she has given up. Aim to withdraw the lamb with a smooth, rather than a jerky, action. The ewe may be laid down on her side when actually delivering the lamb, so that her own contractions will assist with the birth.
The delicate tissues of the uterus and birth canal must always be protected from the hooves of the lamb by cupping the feet in the palm of the hand when manipulating them. The lamb's teeth can occasionally cause damage when the head is roped, as this tends to open the mouth. Some lambs, such as Scottish Blackfaces, are born with sizeable horn buds which can cause considerable damage, especially if they are born backwards. For the purposes of the following discussion it will be assumed that the specific problem facing the ewe and the shepherd has been identified from an initial examination. It is not possible to cover all eventualities, nor is it possible to give anything other than general advice in a book of this type. There is no substitute for on-the-job training, supervised by a knowledge¬able and experienced shepherd, backed up by some formal training from the ATB or the local agricultural college. It is also taken for granted that strict hygiene will be observed, that lubricants will be used liberally and that every ewe will be given antibiotic treatment following any interference.
Where a ewe has been examined and the lamb is found to be alive and presented normally, the birth canal is fully relaxed or in the process of opening up and the ewe is correct in every other way, then she should be left to get on with lambing in her own good time. Regular observations—not internal examinations—will show whether she is making progress. Further interference will only be necessary if no headway has been made after an hour or two.

Young ewes

Ewe lambs and gimmers lambing for the first time will generally take longer to deliver than experienced older ewes. They need more frequent observation prior to, during and immediately after lambing, to see that they are looking after their lambs adequately, as the process is a whole new experience for them. The general rule should be to examine young ewes earlier if a problem is suspected, but to allow them more time to lamb if the examination shows that all is well.
Above all, keep calm, for a panicky atmosphere in the lambing area is highly 'infectious' and will upset the ewes at a time when they should be quiet and relaxed. Foolish mistakes are more likely to be made in a panic. There are relatively few situations which constitute an emergency warranting immediate correction. If the lambs are in the uterus or returned to it with their umbilical cords intact, they are unlikely to come to much harm for some time.

Special notes

Do not attempt any corrective manipulations if, from your initial examina¬tion, you feel that you will find it difficult to sort the problem out. Do not continue to manipulate inside a ewe for more than five or ten minutes at most. Give first regard to the welfare of both the ewe and the lambs and consider also the value of a ewe with twins at foot. There is no disgrace in being 'beaten' by a difficult lambing, but it is disgraceful to injure or kill animals through a pig-headed attitude that 'no ewe has ever beaten me'.
The sheep specialist in your veterinary practice will be experienced in dealing with every difficult situation. Should a caesarean section be the best option, for example, then one can be performed quickly and simply at the surgery, with a very good chance of a successful outcome, provided that half the parish have not already had a go at lambing the unfortunate ewe.
Generally speaking, the longer the time spent in trying to lamb a ewe, the poorer the chances of success. By success, is meant living, viable, uninjured lambs and a live, undamaged ewe which will not succumb to infection, is capable of milking and looking after her lambs and of breeding again the following year.

Correcting Specific Problems at Lambing and Delivering Lambs

The following are a selection of the more common difficulties which arise at lambing and a guide on how to deal with them. It is assumed that the lambs are alive unless stated otherwise.

OVERSIZED LAMBS

Lambs may become jammed in the birth canal because of their large size in relation to the dimensions of the ewe's birth canal, particularly in the region of the bony pelvis. This may occur especially with a large single lamb in a ewe lamb or gimmer, or with a normal sized lamb in a small ewe. The sticking points come when the head, shoulders or hips of the lamb reach the bony pelvic inlet. These lambs are particularly prone to damage, especially from crushing of the head, which can lead to brain haemorrhage. The easiest cases may only require a gentle pull, whilst in the worst cases there is obviously no way that the lamb can be born per vagina and a caesarean section is the only alternative if the lambs are alive.
Assuming the lamb is presented in the normal forward position and it is judged that it will come with a little help, then very gentle traction should be applied to the fore legs, whilst at the same time rotating the lamb first one way, then the other. Up and down movements may also assist. Great emphasis is often placed on the necessity of pulling lambs out in a downwards direction—that is, towards the udder. However, in practice, using modest leverage and rotation can work wonders, especially where so much lubricant is used that the lamb almost floats out! Applying traction to one leg and then the other may also help considerably.
Care must be taken with the feeding of ewe lambs and gimmers to ensure that their lambs—especially singles—do not grow too big and thereby cause lambing difficulties. Late pregnancy feeding can be started earlier than in the ewe flock, but at a lower level. Where ewes are scanned for foetal numbers it is just as important to feed appropriately for singles as for twins or triplets.
A problem which occurs with oversized lambs presented backwards (hind limbs first) is that the umbilical cord may become trapped between the lamb's belly and the ewe's bony pelvis and so cut off the lamb's blood supply. The lamb may be stimulated to 'breathe' whilst its head is immersed in foetal fluids as the blood supply is nipped off. This is obviously a life-threatening situation and a difficult one to deal with, since to dawdle is risky and to rush increases the chances of other types of crushing injury. If in doubt, return the lamb to the uterus if possible and seek veterinary advice. Turning a lamb right round in the uterus should not be attempted, as there is a con¬siderable risk of damaging the ewe.

FORWARD PRESENTATION WITH ONE OR BOTH LEGS BACK

In a normal presentation the front legs are partially extended so that the feet are forward of the lamb's nose. However, one or both legs may not be as far forward as they should be because the elbows are excessively bent, or they may be left completely behind in the uterus, with only the lamb's head in the birth canal. Where there is excessive bending of the joints, the slender shape of the fully stretched out lamb is lost and the elbow and shoulder regions may stick in the ewe's bony pelvis, so halting progress.
Where the feet are in the birth canal and there is sufficient room, an attempt can be made to draw each leg forward individually, by cupping the hoof in the palm of the hand to protect the birth canal from injury. If this is not possible, slip a lambing rope onto one or both limbs and push the head back just far enough to allow the legs to be drawn forward. Again, protect the ewe from damage by cupping the feet in the hand whilst you are pulling on the ropes. If it is difficult to rope the limbs, then return the lamb to the uterus and draw both feet forward by hand, making sure that the head follows (see the next section).
If the fore legs are left far behind in the uterus (Figure 7.2 and Plate 7.17), so that only the head is in the birth canal, then the head must be returned to the uterus, since there is no room to insert the hand and arm past the head in the passage and at the same time manipulate the legs into position. The legs can then be drawn forward individually into the passage, hopefully followed by the head.
Sometimes the head alone, or the head and one leg, may be poking out of the vulva and the ewe is unable to progress further (see Figure 7.3 and Plate 7.18). It is often possible to lamb a ewe with only one leg forward using gentle traction and rotation, providing the lamb is not too big. If this is not possible, then the lamb should be returned to the uterus and the second leg brought forward in the manner already described.
If the lamb's head has been outside the vulva for some time, it may have become very swollen due to the constriction of the vulva around the neck. Lambs may appear gross, with the eyes bulging and the tongue swollen and sticking out. Although they may appear cold and dead, lambs can neverthe¬less survive for quite long periods in the 'hung' position. Often the head is

Both legs back - The Veterinary Book for Sheep Farmers

Figure 7.2 Both legs back.

Head only presented, with both fore legs left behind - The Veterinary Book for Sheep Farmers

Plate 7.17 Head only presented, with both fore legs left behind. The head must be repelled back into the uterus before any attempt is made to draw the fore legs forward. The situation inside the ewe is diagrammatically represented above in Figure 7.2.

A lamb presented with one fore teg back - The Veterinary Book for Sheep Farmers

Figure 7.3 A lamb presented with one fore teg back.

Presentation with one fore leg back - The Veterinary Book for Sheep Farmers

Plate 7.18 Presentation with one fore leg back. With care, this lamb was delivered without drawing the second leg forward. Figure 7.3 above shows the situation inside the ewe.

heavily contaminated with straw and faeces and it must be carefully washed before it is returned to the uterus. The swelling may make it difficult to get the head past the vulva and back into the vagina. Use plenty of lubrication and allow time for the ring of muscles in the vulva to relax, so that tearing does not occur. Try rubbing hard margarine into the hair of the lamb's head and neck, as this is an excellent lubricant which does not get squeezed off during the process. Because the head is so swollen it may be impossible to push it back through the bony pelvic inlet. Patience is needed to simply hold the lamb's head in the vagina of the ewe for some minutes until the swelling subsides somewhat.
Unless the ewe is completely exhausted, she will probably continue to strain and this may help to reduce the swelling more quickly. An assistant should support the ewe in the upended position whilst this is being done, but she can be laid on her side for the delivery. It is best to have the lamb's head roped for easier retrieval. Always bring both fore legs into the vagina before attempting delivery. Once born, the lamb will need careful supervision after its ordeal.
If the lamb is dead, then it is often easier to remove its head before pushing it back into the uterus. However you must obviously be positive that the lamb is dead. As this is a difficult and unpleasant task, it is better to take the ewe down to the veterinary surgery. If you do attempt this your¬self, beware that the bones in the stump of the neck can tear the uterus or birth canal unless great care is taken. Therefore, the legs should be brought forward into the vagina and roped individually and the hand used to pinch the loose skin together to cover the stump of the neck. The dead lamb should be withdrawn very gingerly, checking frequently to see that the hooves are causing no damage. Needless to say, copious lubrication is essential.

PRESENTATION WITH THE HEAD BACK

A relatively common and often singularly frustrating lambing problem arises when one or both fore legs are present in the birth canal but there is no sign of the head, which remains in the uterus, twisted around and facing the wrong way (see Figure 7.4). The legs should always be returned to the uterus—having first attached a lambing rope to each—since there is never room enough for the hand to manoeuvre the head through the bony pelvis and into the birth canal.
The head should then be straightened out so that it is pointing in the right direction and resting on the fore legs, as in a normal presentation. Some considerable difficulty may be experienced in doing this and patience is required. On no account should the jaws of the lamb be used as anchor points to pull the head round, since they are very easily dislocated and fractured. Lambs with broken jaws cannot suck and will probably perish. Whilst it may sound unlikely, it is much safer to use the hard, bony rim of the eye sockets as anchorage points. Use the thumb and middlefinger— making sure the nails are short—and very gently, but firmly, slip them into

The tegs must be returned to the uterus before any attempt is made to bring the head forward - The Veterinary Book for Sheep Farmers

Figure 7.4 Head back. The tegs must be returned to the uterus before any attempt is made to bring the head forward. This is often a most difficult and frustrating manipulation and requires patience and great care.

the corner of the eye sockets and draw the head around. This is always more difficult than it sounds. The temptation is then to draw the roped fore legs back into the birth canal and to hope that the head will follow. However, more often than not, the head flops back into the uterus each time the lamb is drawn forward. (It is almost as if the neck has a permanent kink in it from lying twisted for a long period.) As there is no room for the hand to both draw and guide the head, a rope should be passed behind the ears and looped through the mouth in the first instance. Take up the tension on all three ropes and draw the lamb forward, alternating the pull on each leg. Use the hand inside the ewe to protect her from damage and also to keep the lamb's head coming correctly.

BACKWARDS PRESENTATION

In this position (see Figure 7.5) the lamb is coming hind feet first. In the majority of cases the lamb is the correct way up—that is, its spine is nearest the ewe's spine. (This position is often and quite wrongly called a breech, which is something quite different—see below.) Most ewes can lamb this way perfectly satisfactorily on their own, since it is not an uncommon presentation, especially with twins and triplets. The important thing about lambs coming backwards is that they are at

Backwards presentation. There is some risk to the lamb with this presentation - The Veterinary Book for Sheep Farmers

Figure 7.5 Backwards presentation. There is some risk to the lamb with this presentation.

some risk if they get stuck halfway out, due to the umbilical cord being crushed against the bony pelvis (see earlier). Once these lambs have reached the point where the hind limbs are well outside the ewe and the lamb's rear end has 'seen daylight', they should be drawn away if the ewe is not making progress. Pulling on one hind leg at a time has the effect of narrowing the diameter of the lamb's pelvis. Some gentle rotation and up and down leverage of the lamb during withdrawal usually helps. You must supply extra- generous lubrication before attempting to deliver these lambs because of the high risk of suffocation should they become jammed halfway out.
It is a popular misconception that lambs coming backwards must be completely turned around and delivered in the normal forward position. This is both incorrect and unwise, since there is little enough room inside the ewe, especially when another lamb is present, to correct even relatively simple positions, never mind such a difficult and risky one.

BREECH PRESENTATION

This occurs when the lamb is coming rear end first with both fore and hind limbs pointing forwards (see Figure 7.6). Usually the lamb's spine is uppermost when the ewe is standing. The ewe is obviously in labour, but making no progress, and no part of the lamb, except perhaps for the tail, may be showing at the vulva. On internal examination, the lamb's rear end is found to be wedged against the bony pelvis. The aim is to deliver the lamb backwards, so it must first be pushed gently back into the uterus. Then locate a hind limb, grasp the hock and push upwards and forwards very carefully. Slide the hand down to the foot, cup it in the hand and bring the foot up into the birth canal, whilst maintaining an upwards and forwards pressure on the lamb. Repeat with the other hind foot and then deliver the lamb as described above for backwards presentation. Where another lamb is present in the uterus, this is a tricky manoeuvre, so do not hesitate to seek veterinary advice.
Occasionally, only the lamb's hocks may be presented in the birth canal, rather than its hind feet or tail. Ease the lamb gently forwards towards the uterus by pushing on the point of both hocks simultaneously. Then slide a cupped hand under one hoof, whilst at the same time pushing upwards and forwards on the point of the hock, so that the foot can be brought into the birth canal. Repeat with the other foot and then deliver the lamb backwards.
A similar but even more difficult situation arises when the lamb's back is presented at the bony pelvis, so that on examination of a ewe which has been making no headway, only the spine can be felt. Generally speaking these awkward cases should be brought out backwards, since it is usually easier and obviates the need to worry about the head flopping back, as often occurs in a forward presentation. Upending the ewe greatly assists in correcting the position of all these difficult presentations, even if the ewe is then laid back down on her side for final delivery of the lamb, so that she can assist with her own strainings.

Breech presentation - The Veterinary Book for Sheep Farmers

Figure 7.6 Breech presentation.

Twin lambs, one in a normal presentation, the other coming backwards but upside down - The Veterinary Book for Sheep Farmers

Figure 7.7 Twin lambs, one in a normal presentation, the other coming backwards but upside down. Such entanglements can be difficult to sort out and great care is required to avoid damaging the ewe or the lambs.

MULTIPLES

In the majority of cases of twins and triplets, the lambs come one at a time in a nice orderly fashion, a number of them being born backwards. The relatively smaller size of multiples in most cases means that oversize is generally less of a problem.
However, all sorts of entanglements can occur when more than one lamb tries to enter the birth canal at the same time and the shepherd's task is to decide which bits belong to which lamb and which lamb to deliver first (see Figure 7.7). Sometimes this is relatively simple, but at others it may be particularly difficult, especially against the ewe's straining. Always upend the ewe, since this makes any repositioning of the lambs much easier. Keep the hand in contact with the lamb until you are quite satisfied that you have sorted out which bits belong to which and use lambing ropes to identify heads and limbs. Moderate tension must be kept on ropes or they will tend to slip off, especially if you are using adequate lubrication.
In testing whether you have the lambs sorted out, pull gently on the ropes whilst using the hand inside the ewe to check that all is well and to protect the ewe from damage from the lamb's feet. Tensioning the ropes attached to the lamb to be delivered first allows a second lamb to be pushed back into the uterus, should it be crowding the exit. Obviously, every care must be taken to avoid accidentally pulling two lambs into the birth canal at once, since this is all too easy.
Providing a second or third lamb is presented normally and the ewe has not had a difficult time—which might have exhausted her so that she does not strain—then it need not be delivered by hand. This gives the ewe a chance to lick and mother-up her first lamb and perhaps allow it to suckle before any further lambs are born. The presence of another lamb in the birth canal should re-stimulate the ewe's mothering instincts so that she pays the new lamb proper attention.
In cattle, there is a condition known as freemartinism. This occurs where a bull and a heifer calf, born as twins, share the same blood supply during pregnancy. Male hormones circulate earlier than the female hormones, and thus four out of five of the heifer calves fail to develop a full set of reproductive organs and are therefore sterile. Fortunately—in view of the large proportion of multiple births—this is a rare condition in sheep, since there is usually a separate foetal blood supply for each lamb.

DEFORMED AND DEAD LAMBS

Fortunately, grossly deformed lambs which present a problem at lambing are relatively uncommon. When they do occur it is usually a matter of the lamb being too misshapen to be born through the birth canal. If the lamb is alive, then a caesarean section may be required. If it is dead, then your vet¬erinary surgeon may decide to cut up the lamb inside the ewe (embryotomy) so that it can be removed in pieces. On no account should this technique be attempted by the shepherd.
Otherwise normal, although dead, lambs come in a variety of forms. Some are freshly dead and hence still flexible, and many of these can be removed via the birth canal with lubrication and gentle traction. It is almost always more difficult to manipulate a dead lamb, since it lies like a lump and cannot assist in its own birth. If the lamb has been dead for any length of time, then it is quite likely to have become dried up or mummified.
Providing the lamb seems capable of passing through the birth canal, then the secret lies in adequate lubrication. Hard margarine is very useful in many of these cases. Take a walnut-sized lump at a time and rub it well into the dried out coat of the part of the lamb which is in the birth canal. Push the lamb very carefully back inside the uterus and then coat the whole lamb with the margarine. Conventional lambing gel or cream can then be poured into the ewe and the lamb withdrawn, making full use of rotation and leverage to assist in the process. If you feel the slightest 'dragging' on the tissues, stop immediately and provide more lubrication.
Some dead lambs become stiff jointed (ankylosed) and it is usually not possible to deliver these without straightening out the joints (by breaking them) or cutting up the lamb. Your veterinary surgeon should deal with these cases. Other lambs again may have been dead for some time and become infected. This may be due to a blood-borne infection inside the closed uterus, such as one of the abortion agents, or by infection getting through the open cervix and into the uterus close to lambing. The infection may cause the lamb to swell up and putrefy, and such lambs cannot be delivered by the normal route and must be removed in pieces. Some lambs may come apart when any pull is exerted upon them. It is particularly important that the ewe's uterus—which may be especially fragile due to the presence of infection—is not injured or torn in trying to extract the rotting lamb. Peritonitis would inevitably follow, which would seriously threaten the ewe's life.
Beware of the risk of infection to yourself when dealing with these cases. Use a plastic arm-length glove if this is feasible, but in any case wash extra thoroughly after any such interference. The ewe will, of course, require antibiotic treatment. Remember also that it is not unusual for a live twin to be born alongside a dead one. This may occur with both enzootic abortion of ewes and toxoplasmosis, as well as with other less sinister infections.

A deformed 'headless' lamb - The Veterinary Book for Sheep Farmers

Plate 7.19 A deformed 'headless' lamb.

A deformed swollen (oedematous) lamb - The Veterinary Book for Sheep Farmers

Plate 7.20 A deformed swollen (oedematous) lamb. Such distressing cases can cause serious lambing difficulties and veterinary assistance should always be sought.

'TWIST' OR TORSION OF THE UTERUS

Possibly because of the vigorous movements of the lamb as the time of birth approaches, a condition sometimes occurs whereby the uterus and its contents twist around its longitudinal axis through 90 or 180 degrees. The effect of this abnormal movement is to very effectively block the way out for the lambs through the cervix and vagina. The uterus can still contract down on the foetal lambs in an effort to expel them, but there is nowhere for them to go. Hence there is no pressure on the cervix from the waterbag or from the lambs and consequently it does not relax and open. Since no part of the lamb enters the vagina, the ewe is not stimulated to contract her abdominal muscles.
The shepherd therefore sees a restless ewe, which does not settle down or begin to strain. On examination, the birth canal is found to be partially or wholly blocked. The cause may not be immediately obvious, but on care¬ful examination the corkscrew effect in the vagina will be detected. It is important that ewes which have obviously begun the first stages of labour (but are not straining) are examined, since delaying too long may jeopardise the lambs.
Obviously, the twist must be corrected before the birth canal can fully open to allow the lambs to be born. In a number of these cases the cervix does not open properly even after the twist has been corrected, or it may do so only very slowly, since the uterus is often exhausted and has stopped contracting down on the lambs. In these cases a caesarean section is indicated to save the lambs, so it makes sense to take the ewe to your veterinary surgeon in the first place.
If you deal with this problem yourself, on no account should any attempt be made to untwist the uterus by internal manipulation only, as this is not possible and will damage the ewe in the process. The ewe herself must be rolled around the twist. This is done by laying the ewe on her back and having an assistant rock her gently from side to side whilst you keep your lightly clenched fist in the vagina to detect when the twist is corrected. If it is then possible to insert the hand through the cervix, then do so to see if the lambs are alive. If so, allow the ewe time to fully relax and open up the birth canal. This may take several hours and will involve the ewe straining, so she should be observed frequently. The majority of ewes will lamb satisfactorily if given time.
If it appears that no progress is being made, then re-examine the ewe internally. If the birth canal is still only partially open, or if the afterbirth has begun to separate, then refer the case to your veterinary practice, so as not to threaten the lamb's survival any further.

Aftercare for Ewes Assisted at Lambing

If a ewe has required assistance at lambing, this interference will have put her at risk in a number of ways. Firstly the normal lambing process has been interrupted, so it is important to know if any more lambs are yet to be born. Do this simply by feeling inside once more with a clean hand. If any remaining lambs are alive and presented normally, then leave the ewe to complete the job on her own, but keep her under close observation. If there is anything untoward, such as a second lamb coming backwards or a dead lamb, then deliver any lambs which remain.

HAEMORRHAGE

Lambing is normally a surprisingly bloodless affair, so if abnormally large quantities of fresh or clotted blood are present in the birth canal or on the bedding of the pen, it is probable that the ewe has been damaged. Call out your veterinary surgeon immediately—do not, on any account, transport a haemorrhaging ewe to the surgery. Do not repeatedly insert the hand into the vagina or pack it with cotton wool, since this will disturb any clotting which may be taking place. Simply pen the ewe up with her lambs and leave her undisturbed until help arrives. Damage to the uterus or birth canal is serious and if these tissues have been ruptured or badly bruised then the outlook is poor.

INFECTION

However hygienic you have been, any ewe which has been examined internally will have had potentially dangerous microorganisms introduced into the reproductive tract. There is therefore a risk that the ewe will succumb to infection, especially at a time when her immune defences are low, as they are around lambing time and during lactation. If dirty hands are inserted, then the risk is increased. If the lambing has been a difficult one and tissues have been bruised or torn, the risk of infection is even greater.
Therefore, it is always safest to assume that infection will occur and to give the ewe's own body defences a helping hand by treating her with antibiotics. This can be done immediately after assistance by inserting large antibiotic tablets (pessaries) into the uterus, where they slowly dissolve. However, these are often voided by the ewe along with the afterbirth. It is therefore better to inject antibiotics under the skin or into a muscle. Your veterinary surgeon will be able to supply you with a suitably long-acting preparation to cover most eventualities. If long-acting antibiotics are not used, then daily or twice daily injections will be required for at least three or four days.

PARALYSIS

Occasionally, when a ewe has had a prolonged or difficult lambing, she may not be able to rise. This may be due to sheer exhaustion, in which case rest and 100 ml of 20% calcium borogluconate for injection will do wonders. However, in some cases the ewe may have suffered damage to a large nerve—the obturator nerve—which passes through the pelvis. The nerve may be crushed or bruised during the birth of a large lamb or by the shepherd's large hand during the manipulation of a malpresented lamb. This nerve supplies the muscles which prevent the hind legs from splaying apart. Paralysed ewes may therefore be unable to rise, or if they can do so, they may stagger and fall about. Paralysed animals are usually keen to eat and obviously not sick, which helps to differentiate them from those with other conditions such as milk fever or mastitis. However, care must be taken not to confuse them with fractures or spinal injuries.
The ewe should be made comfortable and provided with food and water within easy reach. A small pen is preferable so that she cannot go too far and get into difficulty. The hind legs can be tied together loosely with some soft rope in a figure of eight, so as to allow the ewe to rise if she can, but to prevent the legs from splaying. If the ewe tends to lie on her side she must be supported by bales to prevent her becoming bloated. Most animals recover within a week, and if they do not the diagnosis should be reviewed.
Meanwhile, the lambs will not be able to suck and lambs must be given colostrum and then milk by stomach tube (not by bottle). They should be kept close to the ewe, but protected so that she cannot fall on them.

Metritis

This is an inflammation of the uterus due to infection with microorganisms. The condition can occur following an assisted lambing where strict hygiene has not been observed, or where the ewe has not been covered with antibiotics after internal interference. Metritis may also occur following a prolapse of the uterus (see later) or where the afterbirth has been retained, particularly when the ewe has been kept in filthy conditions over lambing. It may also occur following abortion with particular microorganisms (such as salmonella), or where the lambs have died and putrefied in the uterus.
One particularly dangerous and usually fatal form of this disease is gangrenous metritis or gas gangrene, which is caused by one of a number of clostridial bacteria. Ewes which are housed or kept in heavily stocked lambing paddocks are at greatest risk. The hind end of the ewe may become very swollen and dark red in colour. There is usually a blood-stained dis¬charge with an unpleasant smell from the vulva. Ewes may breathe rapidly and develop a diarrhoea shortly before they collapse and die; others may simply be found dead. Once this disease has appeared in an unvaccinated flock, more and more cases will appear as lambing progresses. Ewes which have had human assistance at lambing are especially at risk, but the disease also occurs in ewes which have not yet lambed.

CLINICAL SIGNS

Metritis, apart from the clostridial form mentioned above, is usually a chronic condition which grumbles away, possibly for weeks, with small amounts of thick pus discharging from the vulva from time to time. These ewes would probably attract little attention from the shepherd, since they may show no signs of illness. However, some ewes become acutely ill shortly after lambing or aborting, and they stop eating and become very dejected. There is often a putrid smell about them, due to an unpleasant discharge which contaminates the surrounding area. The infection produces a fever and the rectal temperature may reach 106 or 107°F (41 °C). Milk production declines rapidly and the lambs therefore become hungry and neglected. Some ewes may become lame due to a laminitis associated with the infection. If the uterus has been ruptured during lambing, then a peritonitis will follow.

TREATMENT

Metritis is a life-threatening condition which must be treated promptly by your veterinary surgeon using injectable antibiotics and other supportive treatments. Do not be tempted to remove any afterbirth hanging from the vulva and do not put your hand inside these ewes or insert pessaries, since the inflamed tissues are very easily damaged and this would make matters worse.
Bring the ewe indoors with her lambs and make her as comfortable as possible in a dry, warm pen. Feed the lambs by stomach tube or bottle, but leave them with her, or close by, so she can see them. Tempt her with small quantities of tasty food, offered fresh and at frequent intervals. Be sure to provide clean, fresh water where she can reach it if she is down. Keep the pen well bedded and check her udder (hygienically) for any sign of mastitis. These ewes need careful nursing and treatment for a prolonged period.
Unfortunately, some ewes will die despite the most tender loving care and supportive treatment. Others will recover in time, but their milk yield will never fully recover and their lambs will not grow as well as they should.

PREVENTION

The condition is a costly one to the sheep farmer and measures should be taken to reduce the risks of it occurring. To this end, always lamb ewes down in clean, dry, comfortable conditions. Do not interfere unnecessarily at lambing (see earlier). If you have to help, then do so with the strictest hygiene and with the greatest care. Always cover ewes with antibiotics afterwards. If abortions occur in the flock due to an infection likely to cause a post-abortion metritis, your veterinary surgeon will advise you on a suitable antibiotic to use on all aborting ewes. Any ewe which gives birth to dead or rotting lambs should be given a course of antibiotics as a routine. Ewes which have a prolonged or difficult lambing should be observed closely in the days following for any sign of trouble. Ewes which retain their afterbirth should be given antibiotic treatment (see below). Clostridial vaccination should be routine in all flocks and this will help protect them against gangrenous metritis.

Retained Afterbirth

The lambing process is not technically over until the placenta or afterbirth has been voided. In most ewes this occurs within minutes or a few hours of the lambs being born. The placenta is attached to the inside of the uterus at the placentomes or 'buttons' and it is a very intimate connection, involving the intertwining of blood vessels. The tissues separate as a result of the contractions of the muscular wall of the uterus during the lambing process. This squeezes blood out of the blood vessels, so weakening the attachment and allowing the placenta to peel away. This normally starts at the tips of the two horns (or arms) of the uterus and the afterbirth is turned inside out as the separation proceeds.
The separation begins during the second stage of labour, that is, when the uterus is contracting and the lambs are being expelled (this is one reason why it is important that lambing is not held up for too long, since the lambs will die if total separation occurs before they are delivered). Although the ewe normally stops abdominal straining after all the lambs are born, the uterus nevertheless continues to contract for many hours afterwards in order to rid itself of the placenta and other debris. The ewe may resume abdominal straining for short periods, stimulated by the presence of a large portion of the placenta in the birth canal.
The separation process can be halted or delayed for a number of reasons which may lead to the retention of the placenta. The factors listed below are some of those thought to be primarily responsible:

  • infection of the uterus from, for example, abortion agents
  • the presence of dead and putrefying lambs in the uterus
  • premature births, including a proportion of multiples which tend to be born somewhat early; with twins and triplets the lambing process is also prolonged and the muscular wall of the uterus becomes fatigued, so that it may fail to contract effectively
  • prolonged lambings which exhaust the ewe—for example, where there has been some abnormal presentation of the lambs, such as a head back
  • ringwomb cases, or other causes of inadequate relaxation of the birth canal
  • assistance by the shepherd during the lambing process, due to physical factors—such as removing lambs before they are ready to be born or damaging the uterus during the process of manipulating the lambs—and the introduction of infection on the hands or lambing ropes
  • low blood calcium levels (hypocalcaemia or milk fever), vitamin E and/or selenium deficiency, debility of the ewe through poor feeding or disease, all of which reduce or halt the contractions of the uterus

The retained afterbirth will eventually decompose and is usually voided within a week or ten days. Many ewes show no untoward signs during this time so that the shepherd may be unaware that the placenta has been retained, especially if there is none showing at the vulva. Other ewes may be a little off colour and a few may be downright ill from an infected afterbirth causing a metritis (see above).

TREATMENT

Any ewe which does not get rid of the placenta should be treated with long-acting antibiotics by injection until she does so. On no account should the afterbirth be forcibly removed, as this will cause damage to the 'buttons' and possibly reduce the number available for future pregnancies, which would adversely influence the size of the lambs. In the short term it may also lead to haemorrhage. There is nothing wrong in applying a very gentle pull on any placenta which has been hanging out of the vulva for several days to see if it is ready to come away. If it does not flop out with the greatest of ease, then leave it well alone. It will do no harm provided the ewe is treated with antibiotics.
If a significant proportion of ewes in a flock retain the afterbirth, then refer to the above list to see if one or more of the factors mentioned may be involved. There is little that can be done in the case of twins and triplets or the birth of dead lambs, but many of the possible causes are avoidable.
Always promptly remove any placentae or dead lambs from the lambing area. It is not good practice to allow ewes to eat the placenta, as it is highly indigestible. Use ample bedding to cover up any discharge if the pens are not mucked out after each ewe.

Prolapse of the Uterus

This occurs when the whole of the womb is turned inside out and pushed out through the birth canal by the abdominal strainings of the ewe. Immediately after lambing (which is when most prolapses occur) the uterus is a large organ, so it hangs down to the udder as a dark red mass. The cotyledons or 'buttons' are clearly visible on the outside surface, since it is now inside out. It is therefore very vulnerable to damage from being stood on, squashed, torn or otherwise injured. It also becomes heavily contaminated with faeces, mud or straw. The weather is rarely warm at lambing time and the greatest immediate risk to the ewe is usually from shock, because of the rapid loss of heat from the exposed organ.

TREATMENT

It is highly desirable that your veterinary surgeon should deal with this emergency. Meanwhile, the shepherd's immediate concern should be to protect the uterus from further heat loss, injury and infection. This is best done by wrapping the organ in a clean piece of old bed sheeting. If the ewe must be left on her own for a while, then slip the sheet between the ewe's legs and under her belly and tie the ends over her spine. Take the other end and bring it up between her hind legs, enveloping the uterus, and tie the other two corners of the sheet to the knot over the spine. It is preferable if an assistant can restrain the ewe from moving about.

Replacing the prolapse

If you feel confident about replacing the prolapse yourself and have had professional instruction, then the following guidelines may be helpful. Before beginning, inject 100 ml of a 20% solution of calcium borogluconate (with or without added magnesium and phosphorus) under the skin of the ewe (50 ml on each side), since a proportion of affected ewes have low blood calcium levels.
The ewe may be straining, and if not, she certainly will when the prolapse is being returned. Therefore, it is essential that an assistant should up-end the ewe as described in the lambing section—this is always a two-person job. (Your veterinary surgeon will also be able to administer an anaesthetic around the spinal nerves—an epidural—to prevent the ewe straining for an hour or two; this technique will be unavailable to the shepherd.)
If some or all of the afterbirth is still attached to the uterus, then see if it will come away easily—if not, then leave it well alone. Wash as much gross dirt off the prolapse as possible without causing bleeding or further damage. This is best done using large quantities of lukewarm (not hot!) water, without any disinfectants or antiseptics in it, as they might cause further damage to the delicate tissues. Pour the water over the prolapse until it is as clean as is reasonable. Do not attempt to remove any engrained dirt, as this may cause haemorrhage. Gently dab the organ dry with a soft towel or paper towels which don't stick. Do not wipe it dry, as this will also cause bleeding.
Squeeze the contents of two or three intramammary antibiotic tubes over the surface of the uterus and gently distribute it evenly. This acts both to lubricate the organ and also to counteract the inevitable infection which will occur when the uterus is returned inside the ewe.
Using both hands to cup the uterus, gently squeeze it to try to reduce its size, at the same time pushing it back inside the ewe. This is not as daunting a task as it is in the cow, but at times it may seem that it will never go back in. Be patient and take great care not to break off any 'buttons' and not to push any fingers through the uterus, which could be fatal. Work with the ewe, pushing when she stops straining and holding when she does.
When the uterus finally disappears inside the ewe, you are only halfway there. The organ must be turned completely outside in, including the full length of both its horns or arms. Again this will have to be done patiently in between the ewe's strainings. If this is not achieved satisfactorily, the chances are that the ewe will attempt to prolapse the uterus once more and she will probably succeed, whatever you do!
The ewe should be allowed to stand up at this stage and a truss should be applied to try to stop any straining. A prolapse retainer tied to the truss may also help. Stitching the lips of the vulva is not recommended and is in any case a veterinary job. If the ewe decides to prolapse again, stitches will not stop her. She will simply strain and burst the stitches out and be left with a painful, irritating wound which will stimulate her to strain even more.
The secret is to get the uterus positioned correctly and to control infection with long-acting antibiotics given by injection, so that any irritation is reduced to a minimum as quickly as possible. The longer the ewe goes without attempting to prolapse again, the less likely she is to do so. Ewes which do prolapse a second or third time have a poor outlook. Keep the ewe close to home and under frequent observation.
If the prolapsed uterus has been ruptured or torn, it is quite possible for coils of intestine to escape through the prolapse. These cases are always fatal and the ewes should be humanely destroyed on the farm. (See Colour plate 19.)
Prolapses may occur if damage has been done in assisting a ewe to lamb, if infection has been introduced or, in some cases, if the afterbirth has been retained. Acute metritis or vaginitis may cause constant straining and eventually prolapse. Hypocalcaemic cases appear to be more prone to the condition and older ewes are probably more likely to prolapse than younger sheep. Culprits should be marked for culling before the next breeding season.

Mastitis

Mastitis is an inflammation of the udder or mammary gland caused by infectious microorganisms which get into the udder via the orifice at the end of the teat. The disease is frequently disastrous in sheep, because at worst the ewe will die or have to be destroyed and at best she will survive but with a useless half or whole udder. Most have to be culled as being unsuitable for breeding, since they are unable to rear their lambs satisfactorily.
Most cases of mastitis occur immediately after lambing and during the first month of lactation, according to a recent survey carried out by the Royal Veterinary College in London in collaboration with the Veterinary Investigation Service in England and Wales. It would also appear that relatively few mastitis cases occur in the period immediately following weaning. Most of the apparently 'new' cases observed at the pre-mating culling examination probably occurred in the early lactation period. Cases are missed at this time, probably because in many instances the ewes are not obviously ill. It is estimated that, on average, around one in 20 ewes succumbs to mastitis, although in some flocks the figure may be two or three times higher than this.
Mastitis in the ewe—as in the dairy cow—costs the farmer dear. There are costs incurred from ewe deaths, for replacements for ewes culled, from lamb deaths due to starvation, from drugs for treatment and from the restricted growth rate of lambs sucking ewes with sub-clinical mastitis.

CLINICAL SIGNS

In milking flocks, where the udders of ewes are examined twice daily as in the dairy cow herd, cases of mastitis should be spotted quite promptly, and if treatment is implemented immediately then some halves may be saved. However, in most other flocks, cases are often well established before the shepherd is aware of the problem. In fact, the first sign may be lambs looking hungry, or a ewe apparently lame behind, as she attempts to keep her leg away from a swollen and painful gland. In acute cases the affected half of the udder and surrounding area is red, hard and hot (see Colour plate 20). The ewe will probably resent having her udder handled and any examination must be done with care and gentleness. At this acute stage, many ewes will die or become so sick that it is only humane to have them destroyed. In very acute cases, the ewe may simply be found dead.
Following this acute stage, the udder changes colour to purple, then black and becomes cold, clammy and sticky to the touch. The gland frequently becomes gangrenous and large portions of it may fall off (slough), exposing the severely damaged tissues underneath, which will take many weeks to heal over. Ewes which survive this unpleasant process are obviously unsuitable for future breeding, since the affected parts of the udder are either lost or rendered useless for milk production. In the acute stage, when the udder is red and hot, the ewe will usually run a high temperature, but in ewes which are dying, the body temperature will fall drastically in the late stages. There is usually very little secretion in the udder—it cannot be called milk—and as the condition is very painful, no attempt should be made to strip-out the gland. (See Colour plate 21.)
In less severe cases the udder may be swollen but the extreme symptoms just described are absent. The contents of the gland are very variable. In some cases blood and pus may be present and in others a thick or watery secretion. Some may contain something vaguely resembling milk with clots in it. The udders become hard and often contain abscesses which can be detected as hard lumps at a weaning or pre-mating examination. Some of them burst to the surface and pus may leak all over the skin of the udder. This will attract flies in summer and the author has seen such wounds seething with maggots. In some cases the whole of the affected gland may appear to be one huge abscess and pus leaks out of the teats, which may appear twice their normal size. Because the two halves of the udder are completely separate entities, one may remain apparently normal whilst the other may be totally destroyed.

TREATMENT

Treatment of severe mastitis is very unrewarding in the majority of cases and should be aimed at saving the ewe's life, since it is rarely possible to save the udder. If at pasture, the ewe and her lambs should be brought indoors and made as comfortable as possible in a dry pen with deep straw bedding. It is often best to take the lambs away from the ewe, even if only one half of the udder is affected, since it is painful for her to have lambs attempting to suck and there is often insufficient milk in the good half to rear them. The lambs will therefore need to be artificially reared unless they can be fostered-on. Beware, however, that the lambs are not infected with orf, which may have been responsible for their mother's sorry state, in which case they should not be fostered-on to other ewes.
Prompt treatment with injectable antibiotics immediately the condition is detected will be necessary to save the ewe's life. Treatment with intra¬mammary preparations is usually unsuccessful in severe cases. Where there is an accumulation of pus or other toxic secretion in the udder, then your veterinary surgeon may consider surgery to remove the teat or part of the udder (this should on no account be attempted by the shepherd). Antibiotics must be given by injection and a high level of the drug sustained by twice daily injections for several days. Since it seems that the vast majority of cases of mastitis occur during the first month of lactation, shepherds should be especially on the look out for suspicious signs at this time. Undoubtedly, many more cases could be saved if they were detected early and given prompt and vigorous treatment.

PREVENTION

In order to prevent mastitis with any degree of success, it is necessary to understand how and why it occurs, but at present this remains largely a matter of speculation. As in the dairy cow, the udder is likely to be more vulnerable to infection around the time of birth for a number of reasons. It is usually well stocked with milk and there may be some leakage, allowing bacteria easier access to the gland via the teat orifice. Lambs may cause damage to the teats with their sharp teeth, and such wounds become contaminated with bacteria which then act as a reservoir of infection. Orf, spread to the teats from the mouths of infected lambs, may be particularly severe and mastitis is a very common sequel. Vaccination of ewes against orf two months before lambing should be considered where such problems have occurred in previous seasons. (See Colour plate 59.)
Shepherds themselves may spread infection, particularly when they tip ewes up immediately after lambing to see if there is adequate colostrum

Clean hands are essential when examining a ewe to see whether she has milk for her lambs - The Veterinary Book for Sheep Farmers

Plate 7.21 Clean hands are essential when examining a ewe to see whether she has milk for her lambs — otherwise the shepherd may spread mastitis from ewe to ewe.

and milk for the lambs. The hands should be washed before examining each ewe, especially if ewes with mastitis have been examined previously. If the hands cannot be washed, then it is best to leave the udder examination until later.
It is important to reduce the risk of contamination of the udder by faeces. In housed conditions, ewes should not be overcrowded and should be pro¬vided with very generous amounts of clean, dry straw bedding, especially in the lambing pens. A layer of slaked lime on the floor of the pen, under the bedding, will help to both dry and disinfect the area. If a lambing pen has been occupied previously by a ewe with mastitis, it should be mucked out and disinfected, limed and well bedded before being used again. The microorganisms causing the majority of mastitis cases—staphylococci, streptococci, coliforms and pasteurellae—are common wherever sheep are found. Obviously, if an area is highly contaminated, as when there has been leakage from a mastitis-infected udder, the risk of infection of other ewes is much greater.
Mastitis in ewes is commonly caused by Pasteurella haemolitica, a bacterium which also causes pneumonia in sheep. It is commonly found in the tonsils of perfectly healthy lambs and it is thought that the organisms may be transferred to the ewe's udder when she suckles her lambs. In some circumstances this may lead to mastitis and it appears to be more common in ewes suckling twins or triplets. In milking flocks where lambs are weaned early, pasteurella mastitis is less prevalent. However, mastitis due to Staphylococcus aureus is common in ewe milking flocks—just as it is in the dairy herd—being a microorganism which can survive almost anywhere, including on the skin of the udder, on the milker's hands, on milking equipment and in milk itself.
Ewes which have lambed indoors and been turned out to pasture in very poor weather—particularly when it is cold and wet—appear to be at greater risk, especially if they have been excessively crutched. The ewe's defences against disease are lowered around lambing and during much of the lacta¬tion period. Therefore, every effort should be made to reduce the risk of infection through good hygiene and husbandry and by reducing stress on the ewes as much as possible.
Vaccination against mastitis is not practised in the UK, although there is some interest in this technique in Europe and elsewhere. E. coli and Pasteurella haemolytica vaccines for protection against diseases other than mastitis are available in the UK, but there is no evidence that ewes so vaccinated are also protected against mastitis caused by these bacteria.

SUB-CLINICAL MASTITIS

Sub-clinical mastitis refers to a form of the disease in which there are no outward clinical signs. The ewe is perfectly well and the milk appears to be normal in every respect. However, there is a low grade infection of the udder which causes sufficient damage to lower milk yield. The effect of this is to reduce lamb growth rates very significantly. For example, there could be as much as 4 or 5 kg difference in 8 week weights between lambs from uninfected ewes and those with sub-clinical mastitis. As many as a third or more of the ewes could be affected in some flocks. As in the dairy herd, it is thus possible that this form of the disease could be respon¬sible for even greater production loss than the obvious clinical forms of mastitis.
Dry ewe therapy (DET) administered at weaning may help to eliminate these infections, but this has yet to be proved. This technique is discussed in the section dealing with the health of ewes from weaning until mating in Chapter 2.

PUBLIC HEALTH ASPECTS

It is most important that mastitis control and dairy hygiene are rigorously practised where products are sold unpasteurised. Staphylococcus aureus, for example, which is a common contaminant of ewe's milk, may cause serious food poisoning, and there is a long list of organisms which pose an even greater risk to human health.
In the UK there is a small, although vociferous, lobby which insists that ewe and goat milk and milk products should remain unpasteurised, so that the consumer may 'benefit' from their true, natural taste. The facts are that, far from being a 'health food', these products often pose a considerable health risk. To continue to allow the sale of unpasteurised milk flies in the face of sound public health hygiene. The virtual elimination of tuberculosis and brucellosis from the national dairy herd, together with the pasteurisa¬tion of cow's milk, has averted untold misery and death amongst the human population. The level of hygiene in many ewe and goat units selling milk and milk products to the general public falls far below acceptable standards, and the sooner legislation is introduced to prohibit the sale of unpasteurised sheep and goat milk and milk products, the better.

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