Effects of a high energy supplementation based on flaked corn on carcass quality traits and the incidence of dark cutting meat in steers

The aim of this study was to determine the effects of a high energy supplementation based on flaked corn and of the duration of this supplementation, on the concentrations of muscle and liver glycogen and on carcass meat quality characteristics related to dark cutting in steers grazing pasture during the fattening stage. Seventy two steers of dairy origin (Red and Black Friesians), with an initial live weight between 460 and 520 kg were used. Within each treatment (36 steers with and 36 without high energy supplementation), the steers were assigned at random to one of four time lengths of supplementation (7, 14, 21 and 28 dias, 9 steers each). The statystical model used was completely at random with a 2x4 factorial (2 treatments and 4 time lengths of treatment); the interaction diet x duration of the supplementation, the age by dental chronometry and the initial weight of the steers as a covariable were also included. In general, the supplementation resulted in better carcass quality characteristics such as weight, proportional dressing yield, loin eye area and fat cover. Although mean concentrations of muscle glycogen did not differ between treatments, the high energy supplementation reduced the presentation of dark cutters as evaluated through color and pH in Longissimus thoracis muscle.