Post-mortem characterization of Dorper x Santa Inês lambs fed diets containing alternative foods

Resumo

The objective of this study was to evaluate the post-mortem characteristics of lambs fed diets containing alternative foods. Twenty Dorper x Santa Inês castrated male lambs were used.  The experimental diets were composed of ground corn, soybean meal, mineral supplement, urea, and Tifton-85 hay (forage). In addition to these ingredients, cottonseed, sunflower meal, and castor bean cake were used as alternative foods in the proportions of 10, 8, and 8% of %DM, respectively. The experimental design was completely randomized with four treatments (diets) and five replicates (lambs). The experiment lasted 106 days, with 14 days for adaptation and 92 days for evaluation and data collection. At the end of the confinement period, the lambs were slaughtered and the carcasses kept under cooling for a period of 24 hours. The pH and carcass temperature (internal and external) were measured in the Longissimus lumborum muscle. The temperature and relative humidity of the cold chamber were obtained. Muscle pH was altered as a function of diet and reached a value of 5.78 (lower pH) when lambs received the diet with castor bean cake. The internal carcass temperature was higher in the lambs that received the diet containing cottonseed (19.98°C), sunflower meal (19.71°C), and castor bean cake (19.87°C). The muscle pH correlated in a moderate and positive way with the temperature of the carcass (internal and external) and of the cold chamber, in the different diets evaluated. There was positive correlation with values ranging from moderate to high between humidity of the cold chamber and the temperature (internal and external of the carcass; and of the cold chamber). The alternative foods can be used as ingredients in the formulation of diets for Dorper x Santa Inês lambs, as it promoted the proper development of the post-mortem process, which is characteristic of good quality sheep meat.