Abstract

Hogget lamb mortality in the Waihora sheep improvement programme from 1970/80 has ranged from 18 to 35% (mean = 24%). Hogget lambs born during the 1981 and 1982 lambings were used to study the timing, magnitude and causes of lamb mortality. Mean mortality to weaning were 33% and 28% in each year. The distribution of deaths was similar in each of the periods: at birth, born alive but died by day 3 and died between day 4 and docking. Dystocia was the single largest cause of deaths to day 3 accounting for about 13 lamb/100 lambs born. Birth weight was an important factor in lamb deaths with an optimum range of 3.3 to 4.1 kg for minimum mortality.

GH, Davis, RW Kelly, JP Hanrahan, and RM Rohloff

Proceedings of the New Zealand Society of Animal Production, Volume 43, , 25-28, 1983