Farm Table says:
Bruce Farquharson states that “The loss of lambs either at or after birth is unacceptable” and those main losses can be prevented through improved management and feeding of ewes between scanning and lamb marking.
Dystocia, exposure, starvation, and predation are the major cause of perinatal deaths in lambs.
A difficult birth can result in dystocia. This can be caused by:
- Ewe lacking a good pelvic size due to poor growth as a weaner
- Over-feeding ewes in late pregnancy
Adverse conditions such as rain and wind can lead to exposure deaths. This can be minimised by lamb body condition and the provision of shelter. If a ewe is hungry, she may leave her lamb. As well, they may lose contact through predation (foxes, eagles, pigs, wild dogs) or through human presence.
Bruce states the two most important planning factors are ewe nutrition and provision of shelter in lambing paddocks.
Paddocks with pasture cover of 2,000 kgs dm/ha for twins and 1,500 kgs dm/ha for singles is advised.
The following realistic targets for lamb survival are:
- 80% – Twin lamb survival
- 90% – Single lamb survival
- 3% – Ewe deaths
- 5% – Ewes not rearing lambs.