Comparison of Texel- and Suffolk-sired crossbred lambs for survival, growth, and compositional traits.

Texel sheep were imported from Finland and Denmark for evaluation as a terminal sire population relative to the Suffolk breed. The objective was to estimate effects of sire breed on fitness, growth, and compositional traits of crossbred progeny that were serially slaughtered at 63, 105, 147, and 189 d of age. A total of 325 lambs, sired by 19 Texel and 20 Suffolk rams, were born to mature, half-Finnsheep ewes during a 2-yr period. Carcass traits were recorded on 183 lambs. Texel-sired lambs had greater survival to weaning (P = .06) and similar birth and weaning weights compared with Suffolk progeny. Lambs by Texel sires grew 11% less rapidly from 63 to 189 d of age. Estimated accretion rates of carcass fat at 189 d of age were 96.1 and 78.5 g/d for Suffolk and Texel progeny, respectively. Corresponding values for carcass protein were 17.4 and 16.0 g/d. At fixed ages, area of the longissimus muscle did not differ between sire breeds. Texel progeny weighed less at 189 d of age, producing lighter, leaner carcasses of shorter length (P < .05). Compositional differences were not detected when sire breeds were compared at 25 kg of carcass weight. However, Texel progeny had significantly greater depth of fat at the 12th rib and weight of kidney-pelvic fat. Data indicated that Texel-sired lambs deposited proportionally more subcutaneous and less intermuscular fat than did lambs by Suffolk sires. Due to the apparent advantage in lamb survival and the observation that Texel progeny produce lean carcasses relative to the intermediate growth rate and mature size characteristic of the breed, it is concluded that Texel sheep can be used effectively as a terminal sire breed.