A COMPARISON OF GROWTH, CARCASS, AND MEAT CHARACTERISTICS OF JERSEY-CROSS AND FRIESIAN-CROSS HEIFERS IN A ONCE-BRED HEIFER SYSTEM OF BEEF-PRODUCTION

This two-year study compared growth, carcass, and meat quality charact eristics of 57 Hereford x Friesian (H x F) and 45 Hereford x Jersey (H x J) heifers in a Once-Bred Heifer (OBH) beef production system. Live weights for the H x J group at mating, pre-calving, weaning, and final weighing were 26.5 kg, 22 kg, 35 kg, and 37 kg lighter, respectively, than the H x F group. Birth weights of calves from H x J heifer dams were significantly lighter than for H x F dams. Hereford x Jersey heif ers had significantly lighter carcass weights, but similar weight-adju sted dressing-out percentages. At a common carcass weight, H x J carca sses had significantly heavier kidney and pelvic fat, greater fat dept hs over the eye muscle between ribs 12 and 13, and lower carcass weigh t-adjusted femur bone weights. At the same carcass weight, the weights of three major hindquarter cuts were heavier for the H x F group, but the ratio of the combined weight of these cuts to femur bone weight w as significantly lower for that group. Meat quality characteristics di d not differ significantly between the breed-cross groups, although fa t of the H x J group was slightly more yellow and Warner-Bratzler shea r values were slightly lower. In terms of the total systems, it was es timated that H x F heifers were 7.0% more efficient than H x J heifers in terms of carcass weight production per unit of feed dry matter con sumed. It is concluded that Jersey-cross heifers could be used in OBH systems to increase beef production, but that no significant advantage s in animal performance, carcass and meat quality traits, or efficienc y will result from using this heifer genotype relative to comparable F riesian crosses.