Energy coefficients of plant foods for broiler chickens at different ages

Abstract

In order to determine the apparent metabolizable energy (AME), the AME corrected for nitrogen balance (AMEn), the apparent coefficients of metabolization (ACM) of gross energy and the ACM corrected for nitrogen balance (ACMn), an experiment was conducted to evaluate five different plant foods (corn, soybean meal, deactivated full-fat soybean, wheat bran and soybean oil) for broilers at different ages (1-8, 11-18, 21-28, 31-38 and 41-48 days). The method of total excreta collection was used, divided into five metabolism assays. The birds were housed in metabolic cages in a completely randomized design, with five treatments and five replicates per treatment, totaling 25 experimental units. The AME and AMEn values increased with the age of the birds for most foods, except soybean meal. The smaller AMC and AMCn of gross energy were obtained for wheat bran. There was adjustment of the equation to the linear response plateau model for the ACM of corn, soybean meal and deactivated full-fat soybean. The wheat bran and soybean oil were adjusted to the linear regression model. The equations show that the digestibility of energy tends to increase with age, except for soybean meal, which had higher metabolization with younger birds. We conclude that the age of the birds influences the determination of the metabolizable energy of feed.