Determination of nutrient and energy values of cottonseed meal supplemented or not with phytase and protease for broiler chicks

Abstract

The objective of this study was to determine the nutritional and energy compositions of cottonseed meal (CM), with or without enzyme supplementation, for broilers at different ages. A total of 672 male Cobb 500 chickens were distributed into four metabolism and ileal-digestibility trials. The experimental design was completely randomized, with four treatments and six replicates. The following treatments were tested: a corn- and soybean meal-based control diet without enzymes; control diet with enzyme addition; control diet with 25% replaced by CM; and control diet with enzyme addition and 25% replaced by CM. The following variables were investigated: apparent metabolizable energy (AME); nitrogen-corrected AME (AMEn); apparent metabolizability coefficients of dry matter, gross energy, phosphorus, and calcium; apparent ileal digestibility coefficients of dry matter, crude protein, calcium, and phosphorus; and digestible protein of CM. Enzyme supplementation did not affect the energy values of CM. The average values obtained in the pre-starter, starter, grower, and finisher phases were 2,958; 2,554; 1,676, and 1,963 kcal kg–1 for AME and 2,519; 2,282; 1,423, and 1,680 kcal kg–1 for AMEn, respectively. Enzyme addition improves the apparent digestibility coefficients of phosphorus and calcium of cottonseed meal in the grower phase. However, enzyme supplementation does not affect the ileal digestibility coefficients of these ingredients in broilers