GROWTH AND CARCASS CHARACTERISTICS OF ANGUS AND AMERICAN WAGYU STEERS

Ten purebred Angus and ten crossbred (3/4-7/8) American Wagyu steers w ere fed a corn and barley-based diet for 552 days and slaughtered All USDA and Japanese yield and quality grade factors were evaluated and t he amount of extractable lipid and moisture in totally trimmed muscle was determined Angus steers gained 0.9 kg/head/day and American Wagyus gained 0.7 kg/head/day. This difference in growth rate resulted in An gus steers having a heavier final weight (P < 0.05). Angus steers requ ired less feed per unit of gain than did American Wagyu steers. Adjust ed fat thickness over M. longissimus dorsi opposite the 12th rib was a pproximately 3.5 cm and was not statistically different between the tw o breeds (P > 0.05). Average ribeye area and kidney, pelvic and heart fat were similar for the two breeds. The calculated USDA yield grade f or both breeds exceeded 6. Average USDA marbling score was nearly a de gree of marbling higher for American Wagyu than for Angus, but variati on within breed groups was high. Average USDA quality grade was well i nto USDA Prime for all carcasses and did not differ by breed (P > 0.05 ). Japanese yield grade factors were similar for both breeds except fo r cold left side weigh t and the yield estimation which includes an ad justment factor that favors American Wagyu. American Wagyu steers meri ted a higher Japanese marbling score than did Angus (P < 0.05). Beef c olor score, firmness, texture and firmness and texture grade were also different between the breeds (P < 0.05). Fat colour, luster and quali ty were not different (P > 0.05). These data clearly show that some Am erican Wagyu steers have the genetic ability to deposit as much marbli ng as Japanese Black cattle raised in Japan.