Características quantitativas e qualitativas da carcaça e carne de cordeiros submetidos a dietas com níveis de fibra

Abstract

The objective of this work was to determine the ideal neutral detergent fiber (NDF) content that positively increases the carcass characteristics and meat quality of Santa Inês sheep finished in feedlot. The experiment was conducted at the Experimental Farm of São Gonçalo dos Campos, belonging to the School of Veterinary Medicine and Animal Science of UFBA, between September and December 2016. Six hundred intact male Santa Inês sheep were used, with initial mean live weight of 17.0 ± 1.5 kg, distributed in a completely randomized experimental design (DIC), with 5 treatments and 12 replications, totalizing 60 plots. Diets were composed of hay and concentrate, and treatments were represented by NDF levels [20, 32, 44, 56 and 68%, Dry Matter (DM) basis]. There was dietary influence (p <0.05) on the carcass weight (PCQ) and cold carcass weight (PCF), where the PCQ was linearly decreasing and the PCF presented a quadratic form. The PCQ and PCF obtained lower values when submitted to the maximum level of NDF (68%), being the values 10.82 kg and 10.78 kg respectively, and the highest for the diets with 20% and 32% NDF levels, being 18.31 kg and 18.30 kg for PCQ and 18.26 kg and 18.27 kg for PCF. Diets with different levels of NDF caused a difference (p <0.05) in meat protein percentages, which presented a quadratic form with a minimum point at the level of 56.79%. Regarding the conformation of the carcass, the maximum inclusion point of NDF in the diet was found at the level of 29.24%, resulting in an approximate value of 4.18. As for fat thickness, the maximum inclusion point of NDF was found at the level of 33.53%, which did not significantly influence (p> 0.05). Santa Inês lambs fed feedlot can receive diets containing low levels of NDF without negatively affecting carcass characteristics and meat quality. The levels of 27 to 30% of NDF in the dry matter of the ration were the most suitable for sheep termination.