Evaluation of the South African Dorper as a terminal sire breed for growth, carcass, and palatability characteristics1

The South African Dorper is an important terminal meat sire breed in Africa that was recently imported into the United States. The objective of this study was to evaluate the Dorper as a terminal meat sire breed for U.S. production. Semen from purebred Dorper sires was used to artificially inseminate Columbia ewes to produce F1 crossbred lambs. Growth and carcass characteristics of F1 Dorper-Columbia lambs (n = 165), F1 Suffolk-Columbia (n = 89), and purebred Columbia lambs (n = 207) were compared based on subsets of the total number of animals. The F1 Dorper lambs grew significantly slower (313 g d−1) and weighed less (29.8 kg) than F1 Suffolk(357 g d−1, 33.5 kg) and Columbia-sired lambs (328 g d−1, 31 kg) at 77 d of age. However, at a weaning age of 118 d weaning weight and ADG did not differ (P > 0.20) among sire breed groups. Postweaning growth of F1 Dorper (239 g d−1) wether lambs did not differ from that of purebred Columbia wethers (230 g d−1) but was less than that of F1 Suffolk lambs (259 g d−1; P = 0.09). Feed efficiency did not differ among breed types. Breed types had similar dressing percentages (53%), shoulder fat depth (2.8 mm), body wall thickness (3 cm), leg conformation score