Diferentes fontes proteicas, com o uso ou não de taninos de acácia negra (Acacia meransii), na terminação de cordeiros

Abstract

Proper food management is essential to maximize lamb production, which is why the use of alternative foods such as agro-industrial by-products combined with the use of food additives capable of increasing productivity is on the rise in confinement systems. The objective of the work was to evaluate the effect of diets with different protein sources on the characteristics of ingestive behavior, consumption, digestibility, performance, carcass and physical-chemical characteristics of the meat of lambs finished in a confinement system, with or without the use of tannin extract. of black acacia. The research was carried out at the Sheep Farming Laboratory of the Department of Animal Science at the Federal University of Santa Maria. 36 uncastrated male lambs, cross Texel x Ile de France, weaned at 60 days of age were used. These were divided into four treatments composed of two protein sources (soybean meal or canola meal), and with or without the use of black wattle tannin extract, lasting 70 days, with 10 days dedicated to animal adaptation. The experimental design used was completely randomized, in a 2x2 factorial scheme (two protein sources x uses or not of tannin), with 9 replications per treatment. For all variables analyzed, there was no interaction (P≤0.05) between the protein source and the use of tannin extract. The obtained results favored lambs fed with canola meal, when compared to lambs fed with soybean meal for the variables of dry matter intake, organic matter, neutral and acid detergent fiber, total digestible nutrients (4.19%, 4.17%, 1.32%, 0.59% and 3.82%), digestibility of dry, organic matter and protein (81.80%, 82, 26% and 83.70 %), live weight at slaughter (45.43kg), average daily weight gain (0.350kg), hot and cold carcass weight (21.72kg and 21.19kg), subcutaneous fat thickness (3.19mm), color , marbling, shear force (2.84kg), moisture (77.52%) and the ratio of unsaturated and saturated fatty acids (1.33%) of the meat. Regarding the use or not of black wattle tannin extract, the animals fed the diet without the inclusion of tannin obtained the best results when compared to the diet with the addition of 1.6% of tannin extract in the total dry matter for the variables of time spent idle (695.25min/day), consumption of dry matter, organic matter, neutral and acid detergent fiber, total digestible nutrients, live weight at slaughter (46.8kg), hot and cold carcass weight ( 21.77kg and 21.24kg), hot and cold carcass yield (48.82kg and 47.61kg), carcass compactness index (0.33cm), fattening state, shear force (2.88kg) and percentage of polyunsaturated fatty acids in meat (7.35%). Therefore, it is possible to state that canola meal can be used as an alternative protein source, replacing soybean meal in lamb feed. And that the use of tannin extract was not advantageous, in the dosage and in the diets offered to the study animals for the characteristics of consumption, digestibility, performance, carcass and meat quality of the lambs, requiring more research regarding the use of this additive in animal feeding.