COMPARISON OF THREE TERMINAL SIRE BREEDS FOR BIRTH WEIGHT OF LAMBS KEPT UNDER UPLAND GRASSLAND CONDITIONS IN THE NORTHEAST OF ENGLAND

Crossbred females and male progeny of three terminal sire breeds, namely Charollais, Suffolk and Texel, out of Mule ewes (Bluefaced Leicester sires x Scottish Blackface or Swaledale dams) were compared. Analysis of variance revealed that breed, sex and the year of birth were significant sources of variation (P<0.05) for birth weight. Suffolk sired lambs were significantly heavier than the Charollais sired lambs at birth (5.04 ± 0.04 verses 4.88 ± 0.04 kg), whereas they were not significantly heavier than the Texel sired lambs (5.04 ± 0.04 verses 4.93 ± 0.04 kg). There was no significant different between the birth weights of Texel and Charollais sired lambs. The lambs born during 1989 were significantly heavier (5.12 ± 0.05 kg) than the lambs born during 1987 (4.92 ± 0.04 kg) and 1988 (4.86 ± 0.04 kg). Sex and birth date were significant sources of variation as well. It was concluded that breed of sire can affect the birth weight of lambs and this factor should require careful consideration in practical lamb husbandry