Differences among Wagyu sires for USDA carcass traits and palatability attributes of cooked ribeye steaks.

The objective of this experiment was to evaluate the effects of various Wagyu sires on carcass quality traits and palatability attributes of cooked ribeye steaks. Wagyu sires were used and grouped as Old (n = 6) or New (n = 2) sires, based on the chronological order in which they were imported into the United States. One hundred thirteen F1 heifer and steer calves sired by Wagyu bulls out of three different sources of cows were fed a backgrounding diet for 112 d consisting of an 80:20 ratio of roughage:concentrate then grazed on a mixture of orchardgrass and bluegrass pasture for 84 d and finished on a 10:90 ratio of roughage:concentrate diet for 231 d in a feedlot. Progeny from New sires had larger (P < .05) ribeye areas, higher (P < .05) marbling scores, and lower (P < .05) maturity scores than progeny from Old sires. Marbling was positively correlated (P < .05) to brightness (r = .56), texture (r = .60), and fat luster (r = .38). Progeny of New sires had lower shear force values (P < .05) than progeny of Old sires. These results indicate the superiority of New Wagyu sires to produce progeny with more marbling, lower shear force values, and larger ribeye areas than Old Wagyu sires. Furthermore, there are substantial differences between Wagyu sires for carcass quality traits and palatability attributes.