ABSTRACT Two experiments were conducted using direct method to determine the standardized ileal phosphorus (P) digestibility coefficient (SIPDC) of meat and bone meal (MBM) and poultry byproduct meal (PBM) for broilers. In the first experiment, three MBM from different batches were evaluated, with four treatments (MBMI, MBMII, MBMIII, and a P-free diet) and nine replicates of seven birds each, totaling 252 birds distributed across a completely randomized design. The P-free diet was used to determine endogenous P losses. Titanium dioxide (5 g kg−1) was used as an indigestible indicator. In the second experiment, three PBM from different batches were evaluated, with 189 birds distributed over three treatments (PBMI, PBMII, and PBMIII) and nine replicates of seven birds each. These two experiments were conducted when birds were 19-22 days old. The birds were euthanized to collect the ileal content. Using the P-free diet, endogenous P losses were determined at 94.9 mg kg−1 dry matter intake. Standardized ileal P digestibility of MBMI (0.65) and MBMIII (0.69) was higher compared with MBMII (0.49). The SIPDC determined for three PBM sources were similar and 0.96, 0.96, and 0.93 for PBMI, PBMII, and PBMIII, respectively. The present study demonstrates that P in MBM is not as available as it is believed and that the variability between batches should be considered by nutritionists, while PBM can be considered an excellent P source to broiler diets.

ABSTRACT The objective of the present study was to evaluate the effects of xylanase and probiotic supplementation on the performance, carcass characteristics, intestinal pH, intestinal viscosity, and ileal microbiota of broiler chickens fed diets containing wheat bran. The study animals were kept in metal cages, and the study was performed using a completely randomized design, with four treatments, six birds per treatment, and six replicates. The four treatments included a control group, a probiotic-supplemented group, a xylanase-supplemented group, and a group that received both xylanase and probiotic supplementation. The diets of all four groups contained wheat bran (50 and 30 g/kg for the starter and grower phases, respectively) and phytase, and at 10 d after hatching, the experimental birds were challenged orally with Eimeria sp commercial vaccine. During the initial phase, supplementation with xylanase, probiotics, or their combination yielded greater weight gains than the control diet; however, considering the period from 10-35 d, the chickens receiving xylanase + probiotic and the diet without the additives showed lower weight gain (2.746 and 2.600 kg, respectively). All the supplemented diets reduced cecum viscosity, and supplementation with probiotic showed a significantly lower pH (6.11). The ileal microbiota was also influenced by xylanase and probiotic supplementation, modulating the frequencies of the genera Lactobacillus and Clostridium. The positive effects of supplementation with xylanase or probiotics alone were similar to those of co-supplementation, and no associative effect was observed.

RESUMO. Foi realizado um experimento com frangos de corte fêmeas, objetivando-se avaliar o efeito da utilização de probióticos e simbióticos sobre o desempenho e rendimento de carcaça e dos principais cortes comerciais e vísceras comestíveis destes animais. Foram utilizados 720 pintos de um dia de idade da linhagem Cobb, distribuídos em um delineamento experimental inteiramente casualizado, com quatro tratamentos e seis repetições de 30 aves cada em uma densidade de 10 aves/metro quadrado (m2). Aos 42 dias de idade foram abatidos dois frangos por repetição, para a avaliação do rendimento de carcaça e suas partes. A inclusão de probióticos e simbióticos na ração não proporcionou diferença significativa no rendimento de carcaça e suas partes sendo equivalente ao tratamento com antibióticos. Não foi observada diferença significativa entre os tratamentos, inclusive nos controles que não receberam qualquer fator aditivo. Da mesma forma os demais parâmetros de desempenho foram equivalentes para os quatro tratamentos, com exceção do ganho de peso, que foi significativamente menor no tratamento probiótico. Conclui-se que esses aditivos são uma alternativa importante na substituição dos antibióticos como melhoradores de crescimento, os quais já foram banidos em muitos países.

ABSTRACT. An experiment was carried out with female broilers, aiming to evaluate the effect of using probiotics and symbiotics on growth performance and yield of carcasses and of the main commercial cuts and edible viscera. A total of 720 one-day-old Cobb chicks, distributed in a completely randomized experimental design with four treatments and six replicates of 30 birds each at a stocking density of 10 birds per square meter (m2). At 42 days old two broilers of each experimental unit were sacrificed to evaluate the carcass yield and its parts. The carcass yield was not affected by the inclusion of probiotics and symbiotics in the diet being equivalent to the antibiotic group. No significant difference was observed among the treatments, even in the controls that did not receive any additive factor. All the performance parameters were similar for the four treatments, with the exception of weight gain, that was significantly lower in probiotic treatment. It was concluded that these additives are important alternative to replace antibiotics as growth enhancers, which have already been banned in many countries.

ABSTRACT Two experiments were conducted to evaluate the apparent metabolizable energy (AME), nitrogen-corrected apparent metabolizable energy (AMEn), and standardized ileal amino acid digestibility coefficient (SIDC) of extruded soybean cake (ESC) at four different extrusion temperatures: 90, 100, 110, and 120 °C. In experiment 1, 300 male broilers were randomly distributed into four treatments (600 g kg−1 reference diet + 400 g kg−1 of SBC at different extrusion temperatures) + reference diet, with six replicates of 10 birds. A metabolic assay using the total excreta collection method was performed from 14 to 23 days to determine AME and AMEn. Quadractic effect of the extrusion temperature was observed, with the maximum AMEn value estimated as 3424.99 kcal kg−1 for 105.58 °C. In experiment 2, 300 male broilers were randomly distributed into four treatments (453 g kg−1 protein free diet + 547 g kg−1 SBC at different extrusion temperatures) + protein free diet, with six replicates of 10 birds. Experimental diets were offered from 16 to 21 days, and at 21days, birds were sacrificed by cervical dislocation for collection of the ileal digesta to determine the SIDC of ESC. The best SIDC values for lysine (0.824%), methionine (0.908%), and cysteine (0.741%) were estimated at 117.72, 114.40, and 107.37 °C, respectively. The other amino acids evaluated showed a linear response, with better SIDC values with increasing extrusion temperatures. The extrusion temperatures affect metabolizable energy and amino acid digestibility of soybean cake for broilers, being important the standardization of extrusion temperature to maximize the nutritional value of soybean cake used in broiler diets.