Effects of dietary energy density and coarsely ground maize supplementation on growth performance, carcass traits and meat quality of capons

This research study was carried out to evaluate the effects of feeding diets containing two levels of metabolizable energy and the effects of adding ground maize in the last month of fattening on capon growth and carcass characteristics. Capons fed the high-energy diet had heavier final body weight at 153 d of age (P <= 0.001), eviscerated and oven-ready weight (P <= 0.001) and higher dressing percentage (P <= 0.05) than capons fed low-energy diets. Some carcass traits of economic importance such as oven-ready weight, dressing percentage and leg percentage were negatively affected by supplemental maize-containing basic diets. Increased energy density tended to increase abdominal fatness only slightly, and the significant differences in live weight were not offset by adverse effects on fatness. Abdominal fat content was similar among dietary treatments, despite the fact that the ratio of protein to energy was not maintained at a fixed level. The breast and thigh skin of capons on diets containing a high level of ME had a higher (a*) value (more red) (P < 0.001), lower (b*) value (less yellow) (P <= 0.001) and lower pH value (P <= 0.01) than capons receiving low-energy diets. Adding coarsely ground maize resulted in a significant (P <= 0.001) increase in skin yellowness and breast muscle pH values.