The objective of this study was to evaluate the effect of the supplementation of xylanase in diets with reduced energy level on the apparent metabolizable energy corrected for nitrogen, determined with laying hens at 14, 36, 60 and 80 weeks of age. Four digestibility trials were conducted, using 80 Hy-line W36 laying hens aged 14, 36, 60 and 80 weeks of age. Birds were distributed in a completely randomized design in 2 × 2 factorial arrangement (energy level × inclusion […]

Four trials were conducted to determine the requirements of available phosphorus (aP) of female broiler chicks from 1 to 10 (exp.1), 11 to 21 (exp.2), 22 to 33 (exp.3), and from 34 to 46 (exp.4) days of age, keeping the calcium:available phosphorus ratio equal to 2:1. In each trial, 480 Cobb broilers were randomly allotted in a completely randomized design with 6 treatments, 8 replicates and 10 birds per pen. The levels of aP ranged from 2.0 to 5.5 g/kg […]

Four experiments were conducted to study the requirements of available phosphorus (aP) for commercial male broilers of 1-10 day of age (exp.1), 11-21 days of age (exp. 2), 22-33 day of age (exp. 3) and 34-46 days of age (exp. 4), at a constant calcium:aP ratio. A complete randomized design was used in each experiment. The experimental diets were fed ad libitum to 8 replicate groups of ten broilers in each. The increments in the levels of aP ranged from […]

Five pen-raised adult female capybaras were used in five digestibility trials in a Latin square design, to determine, for capybaras, the nutritional values of Cameroon grass (Pennisetum purpureum cv. Cameroon); Napier grass (P. purpureum cv. Napier); corn grain; cassava hay, comprising leaves and stems; and palm kernel (Elaeis guineensis) cake. These feedstuffs were provided separately or mixed, in a completely randomized manner, in different experimental periods. The digestibility of each feedstuff not supplied alone was estimated by difference. The animals […]

The objective of this study was to evaluate the requirement of digestible tryptophan for white laying hens in the production stage fed diets of different digestible tryptophan:digestible lysine ratios, as well as animal performance and histological alterations in their reproductive and digestive systems. A total of 280 white laying hens at 29 weeks of age were distributed in a completely randomized design with five treatments and seven replications with eight birds in each. The treatments consisted of a base feed, […]

The objective of this study was to determine the ideal digestible tryptophan:digestible lysine ratio in diets for laying hens from 24 to 40 weeks of age. Two hundred and forty Hy-Line W-36 laying hens at 24 weeks of age were distributed in a completely randomized design, with five treatments, eight replicates and six birds per experimental unit. The digestible tryptophan levels in the experimental diets were 1.57; 1.68; 1.79; 1.90 and 2.01 g/kg, providing ratios of digestible tryptophan:digestible lysine of […]

The objective of this study to verify the physicochemical quality of commercial washed and unwashed eggs, experimentally inoculated on the shell with Pseudomonas aeruginosa and stored at 5 and 25 ºC for 30 days. A total of 384 eggs, classified as large, from light Dekalb White laying hens at 30 to 40 weeks of age, were used. The experimental design consisted of two blocks in a 2 × 2 × 2 factorial arrangement (contamination, washing, and refrigeration) with six replicates. […]

With the objective to establish the best metabolizable energy (ME) intake for layers, and the best dietary vegetable oil addition level to optimize egg production, an experiment was carried out with 432 30-week-old Hisex Brown layers. Birds were distributed into nine treatments with six replicates of eight birds each according to a 3 × 3 factorial arrangement, consisting of three daily metabolizable energy intake (280, 300 or 320 kcal/bird/day) and three oil levels (0.00; 0.75 and 1.50 g/bird/day). Daily feed […]

This study was conducted to evaluate the effect of cottonseed meal supplemented with lysine and enzyme on laying hens performance and egg quality. Eighty Hy-Line W-36 white Leghorns were allotted for 12 weeks in a 2 × 2 factorial experiment in a completely randomized design, including four treatments and five replications with four birds in each. Treatments included: basal diet + 1% lysine + 0% enzyme; basal diet + 1% lysine + 0.025% enzyme; basal diet + 2% lysine + […]

This study was carried out to evaluate the effect of supplementation of probiotics (Lactobacillus acidophilus, Enterococcus faecium and Bifidubacterium bifidum) and antibiotics (flavomicina and staquinol) on diets for broilers from 1 to 42 days of age, reared in clean (new litter) and challenged (reused litter) environments. A total of 768 one-day-old male broilers of the Cobb 500 strain were distributed in a completely randomized design in a 2 × 4 factorial arrangement (2 litter types × 4 diets), totaling eight […]