Lambing the ewes successfully is only a start – if significant numbers of lambs fail to survive, all the investment of money and time is wasted and flock output will be adversely affected. Lamb survival rates vary according to the type of flock, how much supervision is given during lambing time, and in particular the influence of the weather. It should not come as a surprise if wintry weather arrives in January, February or even March in some parts of the country, so plans should be in place to provide sufficient shelter once ewes and lambs are turned out if lambing takes place during these months. Lambing outdoors later during April or even May in high hill flocks at least gives the best chance of getting decent weather – although this can never be a certainty. Surveys have put lamb mortality (including abortion losses) at 12–15 per cent on average across the country. It is difficult to achieve less than 3–5 per cent even with close supervision, but a target of 8–10 per cent should be realistic in well supervised flocks. Unexpectedly bad weather can raise deaths to 20–25 per cent in hill flocks, but this would be a disastrous loss rate, and should be an exceptional event.

Fig. 393 Lamb losses range from 12–15 per cent in the average flock, but it should be possible to reduce this in most flocks, although there will always be a few deaths in even the most intensively supervised flock.

Fig. 394 Post-mortem examination of dead lambs can be very instructive, enabling plans to reduce losses to be drawn up.

Colostrum

Colostrum is the key to a good start in life for lambs. It provides concentrated energy to protect the lamb against cold and to enable growth to start. It also contains important proteins, antibodies and other substances that help protect against bacteria and other harmful organisms to which the lamb is immediately exposed – those which the ewe has met naturally or against which she has been vaccinated. The sooner lambs get their first feed of colostrum, the better (minutes after birth rather than hours).

One of the post-lambing procedures should be to check both of the ewe’s teats to make sure colostrum is present. This also removes the waxy plugs that are usually present in the end of each teat, making it easier for lambs to suck straightaway. Most strong lambs will soon find the teat, but if there is any doubt about whether the lamb will suck, the ewe should be milked out and colostrum given to each lamb either by bottle (rather time-consuming) or using a stomach tube (quick and easy, once you know the technique). The volume of colostrum required for a first feed is:

Most healthy lambs will then go on to suck normally after this initial feed. If they don’t there is probably something wrong with them, or they have been rejected by the ewe, and they will need more care, perhaps by removing them to a hospital pen. A lamb needs about 250ml/kg bodyweight of colostrum in the first twenty-four hours of life, a little less for those in good housing, a little more for those outdoors.

Colostrum Substitutes

There are always ewes with too little colostrum or too many lambs, so a readily available store of colostrum or substitute is essential. Lamb milk powder is fine after the first day, but does not take the place of the first feeds of colostrum. Possible colostrum substitutes include the following:

Checks for Newborn Lambs

Lambs being born without supervision have to take their chance. They may die if they are born with the placenta over their head, or through chilling if the mother does not lick them, or starvation if they do not suck. They may also become mismothered, particularly if the ewes are lambing indoors. However, where lambs are born under supervision, a quick check can pick up potential problems early, as well as making it possible to put a ewe with more than one lamb in an individual pen so that bonding occurs and lambs cannot wander away.

Numbering family groups with a purpose-designed spray marker allows wandering or lost lambs to be quickly reunited with the correct ewe once they have been turned into larger groups.

Recognizing Healthy and Unhealthy Lambs

One of the many important tasks during lambing time is picking out lambs that are not thriving, either because of lack of milk or disease. Healthy lambs look contented and have a full, though not distended, abdomen. When they stand up they give a good stretch – you can be fairly sure that any lamb doing this is fine, and you can devote your time to those that do not look well. Lambs which are not normal or not thriving do not stretch when they stand up, and look hunched up and miserable. Another sign that all is not well is when a lamb constantly shakes itself, which seems to be an indication of prematurity or immaturity. This is different from the constant shaking or trembling shown by lambs affected with border disease (known as hairy shakers).

Castration and Tailing

The view today regarding tailing and castration is that the procedures should only be carried out if there is a real need to do so. For lambs going for meat under six months of age there is no need to castrate; in fact the lambs will make heavier, leaner carcases by not doing so. It should also be unnecessary to tail dock these lambs as there are various chemical methods of preventing fly strike. For lowland breeds of sheep it is likely that females being retained for breeding will be tail docked. For male lambs that may be slow to fatten, some farmers feel castration is necessary to prevent accidental pregnancies, since ram lambs can become fertile by five to six months, and to enable the lambs to finish faster.

The most common method of castration and/or tailing is to apply a tight rubber ring to the scrotum and tail. However, this undoubtedly causes pain for the lamb, and the hope is that a practical method of pain relief will be available before too long. These procedures should not be carried out within the first few hours of birth, as lambs may not suck until the pain has passed. This method is only legal for lambs up to one week old. Other methods, such as the use of a bloodless castrator, can be used without anaesthetic up to three months of age; thereafter the procedures must be done by a vet using anaesthetic. If tail docking is carried out, make sure that this is not done too high so that the remaining tail is not too short – it is illegal to short dock, and sufficient tail should be left to cover the anus of rams and the vulva of ewes.

Specific Problems of Young Lambs

Spare Lambs, Rejected Lambs and Fostering

Managing surplus lambs is made easier when ewes have been scanned so that those with triplets can be matched up with ewes with singles. If a lot of ewes are lambing over a short period the best way is wet fostering – covering the foster lamb with foetal fluids from the adopting ewe, and if possible, letting her lick it before her own lamb is put with it. This method is often successful. If the ewe has a single dead lamb, the long-standing method of skinning the dead lamb and putting the skin on the foster lamb is also often successful, but less so if the ewe has another surviving lamb.

The other method commonly used is to fasten the ewe in a fostering crate so she cannot turn and smell the fostered lamb, which then gradually takes on the smell of the ewe and any other lamb she has. If this method does not work after about forty-eight hours it is unlikely to do so, and ewes should not be confined for periods much longer than this. It is also important that the fostering crates are kept clean and the ewe is provided with water, good forage and concentrates.

Rearing Surplus Lambs

Any lambs that cannot be fostered will need to be reared on milk powder, having ensured that they have had adequate colostrum first. This is an expensive business but can be economic. It is a waste to get to the stage of live lambs being born and then failing to rear them. Commercial milk replacement powders formulated especially for lambs usually achieve good results providing the instructions are followed closely, and all equipment and housing is kept in a hygienic condition. Small numbers of lambs can be reared by bottle feeding several times a day, but larger numbers are best reared using an automatic feeder. Water, hay and creep feed should be available right from the start so that lambs can be weaned as quickly as possible – this will usually be a minimum of five weeks of age, preferably at least six weeks.

Hypothermia and Starvation

Hypothermia and starvation are the most common and important causes of lamb losses in the first couple of weeks after birth. Lambs born to well nourished ewes have internal stores of special fat (brown fat) that can be metabolized to generate heat quickly and keep their body temperature at a normal level. If they get adequate colostrum this also provides a concentrated heat source as well as initiating growth. Lambs born from undernourished ewes, or of below normal birthweight for some other reason (for example a triplet or premature) have poorer stores of brown fat so are at greater risk. Normal body temperature is 39–40°C; lambs with a temperature of 37–38°C are mildly hypothermic, and below 37°C are severely hypothermic.

Hypothermia occurs when lambs get insufficient colostrum or are born in adverse weather conditions, such as cold, wet and windy, where loss of heat is greater than heat generation. In either case, lambs lose body heat, look tucked up and miserable, and eventually cannot get up, become comatose, and die. Starvation is usually the case with slightly older lambs, which have survived the first couple of days but then fail to get sufficient milk either because the ewe has too little or because of rejection or mismothering. Starving lambs also look miserable, and their hip bones are visible. When any post-mortem examination of dead lambs is carried out, the key sign of hypothermia and starvation is that the abomasum (the fourth stomach) is empty: well fed lambs should have clotted milk present. Increased lamb losses should be investigated by your vet to try to establish the cause.

The risk of hypothermia can be reduced by making sure lambs get adequate colostrum, by giving with a stomach tube if necessary, and by making sure shelter is available. Indoors this means avoiding draughts around lambing pens. Outdoors, extra protection can be given by fitting plastic coats that disintegrate after a few days, and/or by providing sheltered areas where lambs can get out of the wind. In addition, do not castrate and tail lambs too early, certainly not within the first hours after birth, as the pain caused by these procedures will put lambs off sucking for a time.

The treatment of hypothermic lambs depends how badly affected they are. If the lamb can hold its head up, feeding with colostrum by stomach tube, then putting it under a heat lamp or in a warming box should be effective. If it cannot hold its head up it is dangerous to give it colostrum by stomach tube since this is likely to be regurgitated and inhaled. In this case, giving an intraperitoneal injection of glucose can be life-saving. Glucose (dextrose) is usually supplied as a 40 per cent solution: this needs diluting before use. The recommended method is to use the same volume of freshly boiled water to dilute the glucose, making a 20 per cent solution, which will be at the correct temperature for injection. The volume given is 10ml/kg bodyweight. Syringes and needles must be sterile and the injection done as cleanly as possible. The injection site is just to the side of and about 2.5cm behind the navel, using a 19g 1in needle pointing backwards at about 45° to the skin.

The lamb can then be warmed up, preferably in a warming box, and fed as soon as it is holding its head up. If a hypothermic lamb is warmed without being supplied with energy, either as colostrum or by injection, it will develop hypoglycaemic fits and die. It is also a wise precaution to give a treated lamb an antibiotic injection to guard against infection.

Watery Mouth

This is a common problem in some flocks, caused by lambs swallowing bacteria from the environment (for example, by sucking at wool when looking for the teat) before they have had a good feed of colostrum. The bacteria are able to pass straight through the stomach to the intestines where they multiply, producing toxins that get absorbed into the lamb’s circulation. These toxins slow down gut movements, leading to the classic signs of drooling and swelling of the abdomen with gas.

Treatment is antibiotic by mouth and anti-inflammatory injection – consult your vet – and has to be rapid to have any hope of success as affected lambs soon collapse and die.

The main way of preventing watery mouth is to make sure lambs get colostrum quickly after birth (minutes, not hours) and to keep lambing sheds and pens well bedded and clean. For flocks that still experience problems your vet may prescribe oral antibiotics to be given to lambs immediately after birth, although this should be avoided if at all possible since mass medication is not a good long-term solution.

Scouring

Diarrhoea can be the result of nutritional upsets, particularly in artificially fed lambs, or infection with bacteria (E. coli, salmonellosis, clostridia), viruses (rotavirus) or protozoa (cryptosporidiosis). Generally, with nutritional diarrhoea, lambs may not thrive very well but are not ill, whereas with infectious forms of diarrhoea they often rapidly become dehydrated and weak and may die in spite of treatment. Lambs may also die before diarrhoea has time to develop if the cause is the clostridial disease lamb dysentery, which can occur if the ewes have not received their pre-lambing clostridial vaccination. If lambs affected with this disease do survive long enough to show diarrhoea, it is bloody in nature.

If lambs are on artificial feeding, procedures for weighing and mixing the milk need to be checked as well as frequency of feeding, possible milk temperature variations, and cleanliness of equipment and pens.

If lambs are ill, you will need veterinary help to determine the cause and decide on possible treatment and preventive measures. Making sure lambs are getting adequate colostrum quickly enough after birth will be a key feature.

Navel Infection

Navel infection will rarely be a problem in lambs born outdoors, unless the lambing field is overcrowded and muddy. For lambs born indoors, navel infection is always a risk, which is why treatment with a product such as iodine is recommended. Iodine application causes the navel cord to shrivel and dry up; if the cord remains wet, it can easily get infected with bacteria from the environment causing swelling, with infection tracking up the cord to the liver, resulting in liver abscesses. Affected lambs look tucked up and miserable, do not thrive, and usually fail to respond to treatment.

If infected navels are a problem, make sure lambing pens and individual pens are well bedded and as clean as possible. Also make sure that the whole of the navel cord is thoroughly covered with iodine, and re-check and spray a second time a few hours later to be on the safe side. Having a lot of ewes with footrot in the lambing pens may be implicated, since the infected feet will contaminate the bedding, so these should be treated on housing (see Chapter 14).

Joint Ill (Neonatal Polyarthritis)

Infected and swollen joints in lambs from a few days of age can be a big problem in some flocks. Although poor hygiene at lambing is often blamed, some very well managed flocks suffer from this problem, so there is certainly more to it, which we don’t fully understand at present. The most commonly implicated bacterium isolated from cases is called Streptococcus dysgalactiae, and this has been found in swabs taken from the vagina of some ewes, so it is possible that lambs get infected during birth.

Affected lambs should be picked out as early as possible and treated with appropriate antibiotic and anti-inflammatory injections (after consultation with your vet). If neglected, the joint surfaces become damaged, making recovery much less likely. Good hygiene precautions including wearing disposable gloves at lambing and for handling newborn lambs may help, together with navel treatment as dis cussed above, and good colostrum management; however, we still do not have all the answers to this problem.

Fig. 460 This lamb has a swollen knee joint as a result of joint ill. Early treatment is essential if it is to be successful.

Fig. 461 Wearing disposable gloves to lamb ewes and handle newborn lambs may help reduce the risk of joint ill.

Fig. 462 This lamb has a grossly swollen hock joint which is unlikely to respond to antibiotic treatment. Veterinary treatment would involve flushing the joint to remove the pus which is distending the joint, but this is rarely economically worthwhile.

Claw Abscess

Occasionally young lambs become very lame, and on examination, one claw is found to be swollen and very painful. When squeezed, pus appears in between the claws. Although it seems harsh, the best treatment is to squeeze any pus out, bathe the foot, and inject the lamb with antibiotic. They usually make a surprisingly rapid recovery.

Contracted Tendons, ‘Bent Leg’ and Broken Legs

Lambs are sometimes born with the joints in the lower part of the leg unable to extend fully, so they walk on the front of their fetlock (contracted tendons). These can usually be corrected if attended to soon after birth, but if left for a few days are much harder to get back to normal.

If the lamb can get on to its toes, things will usually correct themselves, but the condition can be helped by a little physiotherapy, gently stretching the affected joints. If the lamb cannot stand on its toes, applying splints and bandages can be very successful but must be done carefully with plenty of padding to avoid rubbing injuries. The bandages should be removed every couple of days to check progress, and removed as soon as the lamb is able to stand properly.

Bent leg is a slightly different condition, where the upper parts of the legs bend outwards, and the condition must be corrected quickly as the increasing weight of the lamb will soon make things much worse. Again, careful application of splints and bandages to bring the upper part of the legs closer together under the chest can bring success.

Fractured legs also occur, often caused by the ewe treading on the lamb; this is particularly likely if individual pens are too small. If the break is below the knee or hock, it can usually be treated with a splint and bandaging. As highlighted above, be careful to pad the splint well, and check and rebandage every few days as lambs grow quickly and bandages can become too tight. Lambs’ bones heal quickly and the splint can usually be removed after a couple of weeks. Fractures higher up the legs are more difficult to fix and usually require veterinary attention.

Orf (Scabby Mouth)

This viral condition can be a big problem if it infects young lambs, as it can be transferred to the ewes’ teats, predisposing to mastitis. In very young lambs the virus can infect the gums around the erupting incisor teeth but may not be obvious until you see bloodstained froth around the mouth after the lamb has sucked. Although the lesions look severe, lambs usually manage to continue sucking and recover after a few weeks, but the knock-on effect to ewes’ teats with the possibility of mastitis developing may mean that the ewe becomes ill, her milk supply is much reduced, and so lambs may starve. (See Chapter 4 for details on vaccination against orf.)

Trace Element Deficiencies

Deficiencies of copper, selenium and iodine can all lead to problems in newborn or young lambs.

Copper deficiency: In sheep this is a complicated subject, since there is little margin of safety between too little and too much. Further complications arise since there is breed variation in response to copper, so advice needs to be taken before supplementing a flock unless there is a known deficiency. Copper deficiency is actually induced by an excess of molybdenum in the diet, when soil is eaten along with grass. Copper is toxic to sheep in excess so it is not safe to supplement ‘just in case’.

Fig. 468 This lamb has large orf lesions around its mouth. It was on an artificial feeder and many lambs in the group were affected.

Fig. 469 One of a group of lambs being artificially reared with infected orf lesions on its head.

The most common result of deficiency is the birth of lambs with swayback – as the name suggests, affected lambs cannot use their hind limbs properly. Other signs of a possible deficiency are stillbirths, unexplained increased deaths in young lambs, and failure to suck properly, but as these have other causes, laboratory investigation will be necessary.

If copper supplementation is found to be necessary, the most common methods are by injection or boluses given to ewes in mid-pregnancy.

Selenium deficiency: Can also result in the birth of weakly or ‘floppy’ lambs. It can also cause white muscle disease in slightly older lambs (see Chapter 12). If this deficiency is identified, the supplementation of ewes is most usually done by injection or by the administration of a selenium bolus or bullet during pregnancy.

Iodine deficiency: Not very common, but found in some areas. The signs are increased lamb deaths, with lambs showing enlarged thyroid glands at post-mortem examination. Your vet will advise on supplementation with iodine.

Copper, selenium and cobalt, which can all cause ill thrift in growing lambs as well as the problems described above, can all be supplemented by administering a soluble glass bolus containing all three trace elements. This method will not be appropriate for all flocks because of the potential copper toxicity problem in some breeds.

Neurological Problems in Young Lambs

Swayback is one disease affecting the nervous system, but there are others that may be present at birth or which may develop soon afterwards:

You will usually need help from your vet to diagnose and deal with most of these problems.

Fig. 470 This lamb of a few days of age developed a very swollen abdomen…

Fig. 471 …On closer examination it was found that it had no anus – there was just a dimple in the skin where it should have been. Unfortunately it was not possible to correct this, as the blind end of the intestine was too deep within the abdomen to locate it. The lamb was humanely destroyed.

Other Sporadic Problems Found in Young Lambs

Occasionally a lamb is born which has no opening from the rectum to the outside (imperforate anus), so cannot pass faeces. The lamb appears normal initially, but then develops a swollen abdomen and becomes depressed and off its food. Sometimes a small surgical operation done by your vet can be successful in creating an opening, but in some cases the blind end of the gut is too deep in the abdomen to be located.

Another occasional problem is prolapse of the intestines through the umbilicus soon after birth. If such a case is seen before the intestines are damaged it may be possible to save the lamb, but that means taking it to your vet’s surgery. Protect the intestines by covering with clingfilm, and keep the lamb warm by wrapping it in a blanket.