Avaliação de enzimas exógenas na nutrição de ovinos

Abstract

The use of exogenous enzymes is a biotechnology that aims to optimize the production of ruminants, studied to implement and improve the digestibility and rumen degradability of fiber, starch and protein present in food. The objective of this study was to evaluate the effect of exogenous enzymes supplied as feed additive to lambs. The experimental trial was conducted in the sheep and goats sector of Capim Branco Farm, owned by the Federal University of Uberlândia, located in the city of Uberlândia-MG. Five lambs dorper/Santa Inês with mean age of seven months and average weight of 36.4 kg, housed in metabolic cages, were distributed in five treatments: FIBROZYME® (fibrolytic enzyme); AMAIZE® (amylolytic enzyme); ALLZYME® (proteolytic enzyme); MIX (enzymatic complex) and CONTROL (diet without addition of enzymes). The experimental period was divided into 5 phases of 15 days, the first 10 days were used for the diet adaptation and the last 5 days to collect data on water consumption and food, leftovers, excretion of urine and feces and their characteristics and auscultation. On the last day of each phase, the ingestive behavior was evaluated for 24 hours, through visual monitoring every 5 minutes. The animals were distributed in a 5x5 Latin square design. The means of the treatments were evaluated by the SNK test at a significance level of 5%. The dry matter intake in relation to body weight (DMI / BW) and crude protein intake (CPI) and nitrogen intake (NI) were higher in the treatment using the amylolytic and fibrolytic enzymes, and the nitrogen balance (NB) was superior for proteolytic and amylolytic enzyme treatments. The apparent digestibility was high, but without statistical differences, as well as the digestibility of the neutral detergent fiber. Regarding the ingestive behavior, it was observed a longer time in total chewing in the animals consuming the diet with the fibrolytic and amylolytic enzymes. None of the treatments caused changes in ruminal movement. There was a higher concentration of the enzymes alkaline phosphatase (AP) and gammaglutamyl transferase (GGT) in the treatments using exogenous enzymes, indicating a higher hepatic activity. With regard to energetic metabolites, there was a lower concentration of low density lipoprotein (LDL) for the animals consuming diets with addition of the enzyme. The use of exogenous enzymes causes better utilization of nutrients, with high dry matter digestibility, neutral detergent fiber and crude protein.