Product of the Month

Improving newborn lamb survival

The number of lambs reared per ewe is an important factor affecting the productivity of a sheep flock.  Results from the Hybu Cig Cymru (HCC) lambing survey, conducted on 70 flocks in Wales during the 2010/2011 breeding season demonstrated that 49% of total lamb losses occurred at lambing (0-48 hours), 11 % at 2-14 days post lambing and 10% at 15 days post lambing onwards.  The survival rate of lambs is a useful indicator of the level of management applied to both the ewe and neonatal lamb during their respective periods.  Improving animal performance and reducing avoidable physical losses is crucial to the overall profitability of sheep farming.

There is no transfer of maternal antibodies across the placenta in ruminants for the developing foetus.  Lambs are born without protection against disease and are reliant on colostrum containing antibodies against pathogens for the transfer of passive immunity.  Colostrum antibody production is dependent on the ewe being adequately fed and supplemented in late pregnancy.  The transport of immunoglobulin from blood serum to the mammary gland begins several weeks before parturition and reaches a peak a few days before lambing.  The highly permeable gut lining of the newborn lamb allows for large antibody molecules to be absorbed directly into the bloodstream in the first six hours after birth.  This permeability gradually reduces up until 12 hours after birth and thereafter antibodies cannot pass through the gut lining into the bloodstream.  High quality ewe colostrum contains 50 g/litre or more of Immunoglobulin-G (IgG).  Any reduction in the IgG level in colostrum can mean the difference between successful or failure of passive transfer to the newborn lamb.  Colostrum should be provided at 50 ml/kg live weight per feed at birth and every six hours thereafter in the first 24 hours and should be increased by 20-30 % for lambs exposed to undesirable weather i.e. one extra feed.  It is essential that a newborn lamb receives 3 g of IgG after birth.  The three golden Q’s to lamb colostrum feeding are: quality, quantity and quickly.

In addition to providing antibodies which are vital to help protect the lamb against disease, colostrum is a highly nutritious energy source which helps the lamb maintain body temperature and survive.  The two principal causes of early lamb mortality are hypothermia (chilling) and starvation.  The newborn lamb has a large surface area to body weight ratio which makes them susceptible to heat loss.  Lambs born in a cold, wet, windy environment will lose heat at a much higher rate than lambs born in a warm, dry, draft free environment.  All lambs are born with a finite amount of brown adipose fat tissue within their bodies used to keep warm.

10 Top tips for lambing

  1. Body Condition Score: For lowland crossbred ewes increasing BCS from 2.5 to 3.5 can increase scanning percent by 20-40%. For a hill ewe a BCS of around 2.5 is more realistic.
  2. Housing: House and feed according to scanning results. Lambing pens should be dry, draught-free and well-ventilated providing adequate space per ewe.
  3. Colostrum: Good quality colostrum (50 g/litre or more of Immunoglobulin-G (IgG)) should be provided at 50 ml/kg live weight per feed at birth and every six hours thereafter in the first 24 hours. Hygiene during collection, transfer and feeding of colostrum is critical to lamb survival.
  4. Navel dip: Treated with 10% iodine solution as soon as possible after birth (within 15 minutes) with a follow up dip about four hours after birth encouraged.
  5. Milk replacer: Choose one to suit your feeding system, lamb type and growth goals. Ensure it is mixed correctly (temperature, concentration & volume) and consistently to reduce stress and nutritional scours. (20% concentration means 200g powder to 800ml water to make a litre).
  6. Starter feed: Provide ad libitum access to a good quality starter (16/18 % protein) offered from day 3 or after the colostrum phase to kick start rumen development. Little, fresh and often is the best approach and all feed refusals should be fed to older stock.
  7. Water: Ad libitum access to fresh, clean water at an easily accessible height should be provided from birth. Together water and starter intake drive rumen development pre-weaning.
  8. Roughage: Offer good quality straw in a rack (avoid long green hay as this can lead to depressed starter feed intake, delayed weaning and pot-bellied lambs).
  9. Hygiene: Implement procedures for buildings, feeding equipment and personnel and evaluate hygiene management on a regular basis in addition to observing lambs for any signs of ill-health. One third of lamb losses occur due to infections so focus on colostrum and hygiene.
  10. Weaning: Lambs should be 2.5 times their birth weight (9 – 10 kg) at seven weeks of age and consuming 250 g of starter feed per day for successful weaning.