AVALIAÇÃO DE PROGRAMAS NUTRICIONAIS COM A UTILIZAÇÃO DE CARBOIDRASES E FITASE EM RAÇÕES DE FRANGOS DE CORTE

This experiment was conducted to evaluate the effect of different nutritional programs associated to enzyme supplementation (carbohydrases and phytase) on performance and carcass characteristics. A total of 2,016 male broiler chicks of Cobb-500 strain were allotted in third-two pens and fed diets based on corn and soybean meal. A completely randomized design with four treatments and eight replicates of 63 birds each was used. The treatments were designed as follows: T1 - nutritional program recommended for Coob-500; T2 -T1 nutritional program with reduction of 4% of metabolizable energy (ME), 3% of crude protein (CP) and 10% of all amino acids; T3 - T1 nutritional program with 200g/T of carbohydrases and 50g/T of phytase; and T4 - T2 nutritional program with 200g/T of carbohydrases and 50g/T of phytase. The results showed no statistical difference in feed conversion ratio and carcass characteristics for all treatments in the period of 1 to 42 days of age. However, feed consumption, slaughter weight and weight gain were affected, the treatments supplemented with enzymes had greater feed consumption than the treatments without enzyme supplementation, besides the highest slaughter weight and weight gain. In conclusion, the use of carbohydrases associated with phytase enzymes was effective to increase the apparent metabolizable energy of diets based on corn and soybean meal. The addition of enzymes to the diet of broilers led to an increase in feed consumption of 5.18%, and improved weight gain in 4.39%. KEYWORDS: broilers; carbohydrases; carcass characteristics; performance; phytase.