Abstract

The trial objective was to determine if hot carcass dressing out percentage (DO%) calculated as hot carcass weight/live weight, differed with either lamb pre-slaughter live weight (SlLW) or total tissue depth over the 12th rib (GR) and to identify other factors altering DO%. Data from ten experiments showed that SlLW only accounted for small, and measured GR moderate, amounts of variation in DO%. DO% was increased; by increasing the pre-slaughter fasting time; by increasing pasture allowance and by feeding more digestible forages such as clover, chicory or plantain versus grass based pasture. Similar trends occurred with the relationship between GR and DO%. At the same SlLW wether lambs had a lower DO% than female lambs but at the same GR there were no gender differences. At the same SlLW and GR, faster growing lambs had a lower DO%. While many factors significantly altered DO% including SlLW or GR, large amounts of variation in DO% remained unexplained.

AJ, Litherland, RA Dynes, and RA Moss

Proceedings of the New Zealand Society of Animal Production, Volume 70, Palmerston North, 121-126, 2010