Superdosagem de fitase exógena para frangos de corte de 1 a 21 dias

Abstract

The objective of this study was to evaluate the effect of overdosage of exogenous phytase on the performance and intestinal morphology of the duodenum of broilers of 21 days. Were used in 2100 male chicks a day of Cobb 500. The birds were randomly divided into 12 treatments, and the experiment carried out in a factorial 3x4, 3 nutritional matrix (matrix 1 - formulated to meet all the nutritional requirements of metabolizable energy and amino; matrix-2- formulated with a 5% reduction in amino acids, compared to matrix 1; 3- matrix formulated with a reduction of 10% in amino acids with respect to mold 1, both in matrix 2 and 3, other nutrients They were kept identical to the array 1) and 4 supplementation levels of phytase (0, 500, 1500 and 3000 FTU). The performance variables were evaluated: feed intake, weight gain and feed conversion. After 21 days these birds were sacrificed, and collected samples are 8 animals per treatment of a middle portion of the duodenum, these standard samples were subjected to routine histological and morphometric analysis later. Data were statistically analyzed using the Statistical Analysis System (SAS); The test used was the regression and Tukey, where there was interaction between variables was performed deployment. Weight gain increased with phytase in the diet increased due to the positive effect of phytase enzyme has on the nutrient utilization. The villus height and area of absorption were higher in animals fed with the level of 1500 FTU and the relationship villus / crypt was better at the higher level of enzyme supplementation (3000 FTU). The greater villus height should the integrity of the villi stimulating effect due to the enzyme caused by reducing the amount of substrate available to the action of bacteria. The area of absorption was higher due to the benefits that supplementation of phytase enzyme caused on the villi which reflected directly on the area of absorption. It follows that an overdose of exogenous phytase was able to cause improvements in growth performance and intestinal morphology of the duodenum 21 days broilers, and recommended a reduction of 10% of dietary amino acid supplementation of 3000 FTU phytase in broiler diets 1-21 days.