Growth, carcass and meat quality characteristics of beef cattle with 0, 50 and 75 percent Wagyu genetic influence

Abstract

Feeding trials were conducted in two years to compare growth performance, carcass characteristics and quality of meat from beef cattle with 0, 50 or 75% Wagyu genetic influence. The cattle types used in the two years of the study were Continental crossbred steers (0% Wagyu), cattle with 50% Wagyu influence (Wagyu/Angus crossbreds) and 75% Wagyu influence (containing 25% from other European breeds). Cattle were housed in individual pens in the first year and in group pens in the second year. Cattle were fed a backgrounding diet containing 35% barley grain and 65% barley silage with protein, mineral and vitamin supplements until they weighed more than 380 kg, after which they were adapted to a finishing diet consisting of 80% barley and 20% barley silage with mineral and vitamin supplements. Cattle were weighed every 4 wk and at the end of the finishing period they were processed and carcass information was obtained. A three-rib section (10–12) was removed from 41 (year 1) and 44 (year 2) carcasses selected randomly from each group, and Warner–Bratzler shear force was determined. The year-by-cattle type interaction was significant for most parameters; thus all the data were also analysed by year using weight of cattle at initiation of the feeding trial as a covariate for the backgrounding and finishing phases of growth and using carcass weight and back fat depth as covariates for carcass and meat-quality parameters. Weight at the start of the trial influenced most growth parameters and age at slaughter. Continental crossbred steers had higher (P < 0.05) ADG than Wagyu crossbred cattle during the finishing phase (1.47 vs. 0.82 kg d−1) in year 1, but not in year 2. Carcass weights of 75% Wagyu crossbred cattle were lower (P < 0.05) than those of Continental crossbred steers in both years. Warner–Bratzler shear force values were less than 5.3 kg to shear cores of 19 mm diameter. However, 92% in year 1 and 71% in year 2 of the carcasses from Wagyu crossbred cattle graded Canada AAA, and contained more than a "small" amount of intramuscular fat. Thirty percent of the carcasses from Wagyu crossbred cattle in year 1 graded Canada Prime. Only 30% of Continental crossbred steers in year 1 and 10% in year 2 graded Canada AAA. Wagyu genetic influence enhanced marbling in beef cattle without loss in carcass size for the 50% Wagyu steers. Key words: Wagyu, Carcass characteristics, Warner–Bratzler shear force