RESPONSES IN MEAT CHARACTERISTICS OF HOLSTEIN–FRIESIAN MALES TO CASTRATION AND DIET

The carcass characteristics of Holstein–Friesian males (bulls, unimplanted steers, and steers implanted with zearanol) as affected by castration and forms of shelled corn diet (dry, whole acid-treated high moisture, and rolled acid-treated high moisture) and their 2 × 2 interactions were studied. The animals averaged 84 kg body weight at the start of the experiment and were slaughtered at a pen average backfat thickness of 0.76 cm measured ultrasonically between the 11th and 12th ribs. Interaction effects were significant in the percent trimmed loin, flank, hindquarter, shank and total cuts. All carcasses had acceptable lean color, texture, firmness and marbling. The different forms of corn were similar in their effects. Similarly, implantation of steers with zearanol did not produce significant differences. The carcasses of all treatment groups in this study averaged Canada A grade and were essentially of the same quality characteristics. Compared to the steers, however, the bulls required slightly longer on feed but yielded significantly more carcass weight, a greater percent lean, a greater percent trimmed chuck and forequarter cuts, less carcass fat and had a higher lean:fat ratio. The steers yielded a higher percent trimmed loin and also more tender meat as determined by shear tests, but this latter case was not supported by the taste panel. No other differences were observed.