A GUIDE ON PREPARING FOR LAMBING SUCCESS
Lamb losses are detrimental to farm profits. Most occur during pregnancy, or in the first week of life and there are common culprits. The reasons for loss should be investigated and recorded, to help target reductions right up to the point of sale.
Keeping records
Most lamb losses are “invisible” with resorption or abortion of the pregnancy, or death of the lambs after birth. Losses from scanning to docking are commonly around 20%1, which is too significant a number just to be ignored.
In order to reduce this loss, farmers need to keep records from six key times throughout pregnancy and up to sale.
- Mating
Total number of ewes mated.
- Scanning
Number of lambs scanned.
- Docking/tailing
Number of ewes at docking (Compare to ewes at mating as an indicator of ewe deaths during pregnancy or more commonly over lambing)
Number of lambs at docking. (Compare to lambs at scanning. High losses can indicate losses from abortions or losses at birth from dystocia or starvation exposure)
- Weaning
Number of lambs weaned. (Compare with lambs docked. Losses often associated with infectious disease).
- Sale
Number of lambs sold
Number of lambs retained as hoggets. (Compare to lambs weaned. Losses often attributed with worms or other infectious disease).
Trends
The best benchmarking is comparing your own records year on year as well as against national averages (if these figures are available).
Prevention and protection
The records you keep may highlight repeat problems during pregnancy or at lambing time. First, get to know what the most common problems are and how to handle them.
Infectious disease
Infectious abortions account for the majority of all sheep abortions. The two most common offenders in NZ are:
- Campylobacter: A bacterial infection that can cause abortion storms in late pregnancy.
- Toxoplasmosis: Parasitic infection transmitted by cats.
To prevent losses from these common causes of abortion, ensure ewes are fully vaccinated before mating.
Late pregnancy
Observe ewes closely for any signs of peri-natal problems. The more you know about the types of conditions you might have to deal with, the better.
Three of the most common complaints are:
- Prolapse
- Sleepy sickness (Hypoglycaemia)
- Milk fever (Hypocalcaemia)
Lambing
Most ewes should lamb without difficulty. You should try not to intervene, but quietly look out for signs of a problem. This could be:
- Cast ewes
- Mal-presentation or oversized lambs (dystocia)
- Mixed up twins and triplets
- Dead lambs (starvation exposure, often associated with poor ewe condition or low feed levels).
- Deformed lambs
Weather
The weather can play an important role in lamb loss but generally 70% of all lamb loss can be mitigated through management changes (Source: Beef and lamb NZ).
Docking to Sale
Common infectious diseases account for the majority of the lamb loss
- Clostridial disease (vaccinate ewes pre-lambing and lambs at docking and weaning)
- Pneumonia (improve nutrition and reduce handling stress and stocking rates)
Parasites
- Gastrointestinal parasites (ensure you are using an effective drench and drenching program)
- Fly strike (do not let lambs get struck, use effective preventative dips).
Conclusion
The sheep farming system you run and the condition of your ewes will determine both the potential lamb crop and your lambing success. Certainly, good conditioned ewes that are well fed and have a robust health plan will reinforce your efforts to reduce both ewe and lamb losses and contribute to your lambing success.
