Comparative Performance of Castrated Male Lambs from two Crossing-Sire Breeds

Finished lamb production in the UK is based upon the use of terminal sire breeds, selected for carcass characteristics, mated to crossbred ewes, chosen for maternal attributes. Previous experiments have shown that even where good quality terminal sires were used too high a proportion of finished lambs produced carcasses of moderate quality (Merrell, Webster and Ellis 1990; Merrell 1993). Ultimately, an improvement in the carcass attributes of crossbred ewes should help to alleviate this problem. A long term experiment which aims to compare the performance of crossbred ewes bred from two crossing-sire breeds was set up in 1989. During the first phase of this experiment (1989 - 1992) selected ewe lambs were retained to produce the two crossbred ewe flocks, surplus ewe lambs and all wether (castrated male) lambs were finished. Data are presented for finished wether lambs produced during this initial phase.