Abstract

Over 20 years ago, cooperative group breeding schemes screened large gene pools to establish ram breeding flocks. This process invariably exploited differences between animals within a breed and not differences between animals regardless of breed. This paper describes the establishment and operation of Landcorp Farming Limited's Lamb Supreme (LS) terminal sire breeding programme and presents results of a comparative slaughter trial for discussion. In 1989 and 1990 Landcorp screened a total of 3,685 ewe hoggets from 501,000 animals. The progeny from 3 years' mattings of these screened- in ewes constituted the nucleus flock of the LS programme. The progeny of rams from this flock mated to commercial Romney ewes were compared with straightbred Romneys (R) in a slaughter trial in three slaughters from January to May 1994. At the three slaughter dates, LS lambs had heavier pre-slaughter liveweights and carcass weights than R lambs and were no fatter when adjusted to the same mean carcass weight. Net returns averaged more per LS cross lamb than per straightbred R lamb.

GB, Nicoll

Proceedings of the New Zealand Society of Animal Production, Volume 55, , 328-330, 1995