Invasive Species Compendium

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Abstract

Effect of breed of ram on fertility of ewes and perinatal mortality of lambs.

Abstract

114 sires from 8 breeds (3-48 males /breed) were used in 2855 matings over a 7-yr period. The rams were individually mated to 20-25 ewes of mixed age and breed (mainly crossbreds from Cheviot and Scottish Blackface dams, but also some purebred Galway, Border Leicester, Cheviot and Scottish Blackface ewes). For matings involving Suffolk, Texel, Dorset Horn, Hampshire, Oxford Down, Lincoln, Ile-de-France and Dorset Down sires resp., fertility averaged 86.9, 85.9, 89.3, 90.5, 88.0, 94.6, 86.7 and 85.8%, litter size 1.68, 1.68, 1.68, 1.66, 1.54, 1.67, 1.57 and 1.75, lambs born/ewe mated 1.45, 1.44, 1.50, 1.50, 1.36, 1.58, 1.36 and 1.50, and perinatal mortality 8.4, 9.9, 12.2, 10.2, 12.0, 5.2, 8.9 and 10.1%. Breed of ram did not affect any of the traits significantly. The results indicate that Texel rams, which have good carcass characters, could be used as sires for fat-lamb production without affecting the reproductive performance of the ewes mated to them.