GROWTH PERFORMANCE OF LAMBS SIRED BY RAMS OF THE EAST FRIESIAN, FINNISH LANDRACE, ILE DE FRANCE AND SUFFOLK BREEDS

Abstract

Lamb weights at birth, weaning and at 100 and 140 days of age were studied on 82 purebred Suffolk, 673 single-cross and 142 backcross lambs sired by four East Friesian, three Finnish Landrace, 11 Ile de France and six Suffolk rams. These rams were bred to Suffolk, Shropshire and Ottawa (MM) synthetic strain ewes, and to single-cross ewes sired by the same four ram breeds from 1971 to 1974. There was no significant effect of breed-of-sire on weight of single-cross and backcross lambs at weaning or at 100 and 140 days of age. Lambs sired by Finnish Landrace and East Friesian rams weighed less (P < 0.01) at birth than those sired by Suffolk and Ile de France rams. Backcross lambs by East Friesian sires had slightly heavier lamb weights at 100 and 140 days of age compared with Suffolk-sired lambs from backcross matings. Key words: Sheep, breed evaluation, ram, growth, exotic, single-cross, backcross