Interação entre consumo alimentar residual e ambiente térmico sobre o desempenho, composição de carcaça e qualidade da carne ovina

Abstract

The objective was to test the hypothesis that sheep with lower RFI values ​​do not decrease performance under heat stress, without altering carcass characteristics and meat quality regardless of the concentrate level. We used 60 Dorper males previously classified according to RFI and distributed in a block design with plots subdivided into two thermal confinement environments (full sun and shade) and diets with 30, 45 and 60% concentrate, during a period of 60 days. CAR alone did not affect any of the variables analyzed. Animals that received higher proportions of concentrate in the diet showed superiority for all performance variables, characteristics and carcass composition. Interactions between environment and concentrate showed that animals confined to the shade and receiving higher proportions of concentrate retained more nitrogen, higher PF, GPT and ADG. In the interactions between CAR and environment, positive CAR animals presented higher PCQ, PCF, commercial cuts and bone and muscle weights when confined to the sun, in addition, these animals presented higher percentages of polyunsaturated fatty acids in the meat, as well as the sum of omega 3. On the other hand, RFI-negative animals had the highest carcass weights, commercial cuts, bones and muscle when confined in a shaded environment. It is concluded that interactions between CAR and the environment promote changes in performance, carcass composition and meat fatty acid profile.