SUMMARY
This study aimed at evaluating the use of exogenous enzymes in diets with Saccharomyces cerevisiae and their impact on zootechnical performance, carcass yield, intestinal histomorphometry and of broiler diets in the initial phase. A completely randomized design was used in a 2×3 + 1 factorial arrangement, with two levels of enzyme complex (EC), (0 and 200g / ton), three yeast levels (0, 6 and 12%) and a control diet, making up seven treatments, with five replicates of 20 broilers per experimental unit. We evaluated the performance (feed intake, weight gain and feed conversion ratio), carcass yield and cuts, histomorphometry of the small intestine (height, circumference and width of villi, height and width of the crypt, thickness of the intestinal muscle wall and villi/crypt relationship). From 1 to 7 and 1 to 21 days, the inclusion of yeast led to reduced broiler performance. At 21 days, the addition of EC resulted in an increase of (p <0.05) in the thickness of the muscular wall of the duodenum and decreased the width of the crypt in the ileum. The 12% level of yeast without the EC provided a thicker jejunum intestinal muscle wall when compared to the positive control. There was no significant effect on carcass yield and cuts between treatments. In conclusion, the inclusion of yeast reduces performance from 1-21 days. The enzyme complex and yeast does not change the performance or carcass yield, however, it does bring benefits to the intestinal mucosa.
Keywords:
glucanase; mannanase; yeast; villus
