Cottonseed meal in broiler diets with or without enzyme supplements

ABSTRACT This experiment was carried out with the aim of evaluating diets containing cottonseed as a substitute for soybean meal protein, with or without enzyme supplements, on performance and carcass characteristics in broilers. A total of 350 chicks were distributed in a completely randomised experimental design, in a 2 x 2 + 1 factorial scheme (2 levels of substitution: 10% or 20% x with or without enzyme supplementation + control diet), giving a total of five treatments with seven replications. When compared to the control diet, in the pre-initial phase, the chicks submitted to the diets containing cottonseed meal showed higher feed intake and weight gain. However, when the periods, from 1 to 21 days and from 1 to 42 days, were evaluated, the performance of the birds was similar. Over the total breeding period, there was an effect from the level of substitution and the enzyme supplement, where a substitution of 20% and the addition of enzymes resulted in better weight gain. For carcass characteristics, it was found that a diet with 10% substitution and the addition of enzymes increased thigh weight in comparison to the control diet, and a substitution of 20%, gave greater yield of the upper thigh. Greater thigh weight was also found with the addition of enzymes. It can be concluded that cottonseed meal can be used as a substitute for 20% of the soybean meal protein in broiler diets supplemented with the enzymes phytase and xylanase.