2015-01-02   facebooktwitterrss

Plan to Loose Less Lambs

Neonatal mortality continues to run at an average of 15% of lambs scanned so in a 100 ewe flock can be costing you £2,000! Independent sheep vet, Harriet Fuller and Volac young animal specialist, Dr Jessica Cooke advise how neonatal losses can be cut to nearer 5%.

Neonatal mortality, the main causes

  • Stillbirths due to difficult births or infectious abortion agents

  • Starvation – lambs may fail to suck because they are small and weak or because of a difficult birth or the ewe may not have sufficient colostrum or fail to ‘mother’ the lamb

  • Infections such as watery mouth – these usually only occur in lambs that have not ingested sufficient colostrum

  • Hypothermia – low birthweight lambs and those that have not ingested sufficient colostrum are more likely to succumb to hypothermia

Thin ewes generally produce lambs of lower birthweight and with a reduced amount of brown fat reserves compared to lambs from fitter ewes. Furthermore, thin ewes produce less and poorer quality colostrum than fit ewes and do not ‘mother’ their lambs as well. So, poor body condition score at lambing is one of the main underlying causes of neonatal mortality.

Plan ahead now to cut lamb losses says Dr Jessica Cooke of Volac International

Plan ahead now to cut lamb losses says Dr Jessica Cooke of Volac International


Good nutrition

Approximately 70% of foetal growth occurs in the last six weeks of pregnancy. To help meet the ewe’s growing nutritional demands in late pregnancy and early lactation, introducing rumen protected fat to diets is an ideal way of increasing diet energy density and subsequently maintaining ewe body condition.

Scanning enables rations to be tailored to the needs of the ewes and blood sampling ewes three to four weeks pre-lambing will determine if their energy and protein requirements are being met.

Good body condition at lambing

Target body condition score for lowland ewes lambing indoors is BCS 3. For outdoor lambing, a slightly lower BCS of 2.5 to 3 will help minimise lambing difficulties. Poor ewe body condition at lambing usually results from inadequate nutrition or disease, or both. The main diseases causing thin ewes at lambing are lameness, liver fluke, haemonchosis and sheep scab, so it is vital that these diseases are controlled.

Lambs of both low and high birthweight have a reduced chance of survival compared to lambs in the optimal weight range. The very small lambs are more at risk of hypothermia and take longer to stand and suck, whilst very large lambs are at risk of dying during birth or suffering trauma that delays standing and sucking.

Optimal lamb birthweights for 70kg to 85kg ewes mated to a terminal sire lambing indoors

Singles 5.5kg to 7.0kg

Twins 5.0kg to 6.0kg

Triplets over 4.0kg

Good colostrum: early intake is the single most important factor affecting a lamb’s survival. Accumulation of colostrum in the udder is dependent on the ewe being adequately fed both energy and protein in late pregnancy and on the ewe being in good body condition. Fit ewes produce more, better quality colostrum than thin ewes; they also express more maternal behaviour.

Colostrum: minimum requirement

50ml per kg bodyweight within first two hours

200ml per kg bodyweight within first 24 hours

Triplet bearing ewes are a particular problem frequently having insufficient colostrum to satisfy all three lambs’ requirements. Feed either supplementary colostrum collected from other single bearing ewes or artificial colostrum.

Good protection against diseases: take a three pronged approach.

  • Lambs must be born into a clean environment

  • Essentials within the first 15 minutes of life
  1. a feed of high quality colostrum
  2. navel treated with strong iodine

Treating lambs with antibiotics at birth is no substitute for these measures. Routine use of antibiotics is discouraged because of the risk of selecting for antibiotic resistant bacteria.

For diseases such as lamb dysentery, injecting pre-lambing ewes with a booster clostridial vaccine produces specific antibodies in colostrum to protect the newborn lambs. Infectious abortion agents such as enzootic abortion and toxoplasmosis present within a flock usually results in the birth of weak lambs as well as typical abortions. Effective vaccines are available, however their uptake remains relatively low and both these diseases continue to have a significant impact in flock performance.


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