Title: LAMB GROWTH PERFORMANCE OF CERTAIN PURE BREEDS AND THEIR 2-, 3-, and 4-BREED CROSSES
Abstract:Weaning weight, post-weaning gain, and final market weight were studied on 1734 lambs from Romnelet, Columbia, Suffolk, and North Country Cheviot breeds of sheep and their 2-, 3-, and 4-breed crosses....Weaning weight, post-weaning gain, and final market weight were studied on 1734 lambs from Romnelet, Columbia, Suffolk, and North Country Cheviot breeds of sheep and their 2-, 3-, and 4-breed crosses. Several least-squares models were used; all included factors for year, age of dam, sex, birth type, and regression of the trait on age of lamb, and differed in the classification according to the genetic makeup of the lambs. Weaning weights of the purebred, and 2- and 3-breed cross lambs were significantly different (24.4, 25.6, 26.6 kg, respectively). Post-weaning gains of the three mating types were also significantly different but in a different ascending order, 19.4 kg for purebreds, 19.9 kg for 3-breed crosses, and 20.6 kg for 2-breed cross lambs. Final market weights of the purebred, and 2- and 3-breed cross lambs were 43.7, 46.3, and 46.4 kg. Means of the three traits from 3-breed cross lambs were similar to those from 4-breed cross lambs. Lambs sired by 2-breed cross rams did not perform on the average better than the lambs sired by purebred rams. Purebred Suffolk rams sired lambs that were markedly better in the production traits than those sired by the other three pure breeds and were equal to or better than those sired by crossbred rams. Only Suffolk × North Country Cheviot rams sired lambs that outperformed the lambs sired by the Suffolk rams but the differences were small.Read More