This study was developed to examine the performance, carcass and cut yields, nutrient digestibility, and intestinal histomorphometry of chickens fed diets supplemented with protected sodium butyrate until 21 days of age. Two experiments were conducted, both of which involved the following treatments: basal diet with inclusion of an antibiotic; basal diet without antibiotic or protected sodium butyrate (PSB; control); basal diet with inclusion of 225 g/t PSB in the pre-starter and starter phases; and basal diet with inclusion of 300 g/t PSB in the pre-starter and starter phases. In the first experiment, 784 male broiler chicks were distributed into the four treatments, with seven replicates of 28 birds, to evaluate performance and carcass and cut yields. In experiment II, 280 male broiler chicks were distributed into the four treatments, with seven replicates of 10 birds, to evaluate intestinal digestibility and histomorphometry. At 42 days of age, the broilers supplemented with 225 g/t PSB had a higher average final weight than the control group. At seven days, the chickens supplemented with 300 g/t PSB exhibited the highest duodenal villus height; those supplemented with 225 or 300g/t PSB or antibiotic showed the greatest jejunal villus height; and those treated with 225 g/t PSB exhibited the highest jejunal villus/crypt ratio. At 21 days of age, the broilers that received 225 g/t PSB showed the highest duodenal and jejunal villus height. The use of protected sodium butyrate in chicken diets up to 21 days of age improves intestinal development and performance until slaughter age.

O presente trabalho foi realizado com o objetivo de determinar a composição em aminoácidos e os coeficientes de digestibilidade dos aminoácidos da soja integral extrusada, tostada e do farelo de soja reconstituído de óleo. Foi utilizada a metodologia da alimentação forçada (Sibbad, 1976) com galos adultos. Para o cálculo dos coeficientes de digestibilidade dos aminoácidos das sojas testadas, foram consideradas as perdas endógenas e metabólicas obtidas de galos em jejum. Os dados médios de digestibilidade verdadeira de todos os aminoácidos testados foram de 91,1% para a soja extrusada, 78,6% para a soja tostada e 90,5% para o farelo de soja. Os resultados obtidos permitem concluir que a digestibilidade dos aminoácidos da soja integral tostada foi inferior a da soja extrusada e farelo de soja + óleo, que por sua vez foram semelhantes entre si. Portanto, pode-se afirmar que os diferentes tipos de processamentos da soja integral conferem a esse alimento características nutricionais distintas para aves.

The present bird assays were conducted to determine the digestibility of amino acid content of process full-fat soybeans. Two types of process full-fat soybeans were utilized, the extruded and heated full-fat soybeans. The assay was developed by using the force-feeding adult rooster method. The results for amino acid digestibility of the extruded soybean were higher than that heated soybean. As the type of full-fat soybean processing caused differences on the amino acid availability of studied soybeans, it can be concluded that the different processing gave to those feedstuffs diverse nutritional characteristics for poultry.