Abstract

Post-mortem examinations were carried out on 1098 lambs that died between birth and weaning at 12 weeks of age to evaluate the causes of mortality in a high-fertility flock. These comprised 95% of all lamb deaths from a total of 14732 lambs born over nine years. Starvation/exposure was the biggest cause of lamb deaths (26%) followed by infection (20%), hypoxia (16%) and prenatal deaths (16%). Prenatal deaths were 18%, 12% and 10%; deaths due to hypoxia were 18%, 15% and 11% and to starvation were 28%, 26% and 12% for triplets, twins and singles respectively. There were no significant differences between birth ranks for deaths from infection. Keywords: mortality; litter size; birth rank; dystocia; starvation; prenatal; single; twin; triplet; survival; sheep

BC, Thomson, NB Smith, KR Ward, and PD Muir

New Zealand Journal of Animal Science and Production, Volume 80, Online, 21-23, 2020