The effect of diets with mannan oligosaccharides (MOS) and enzymatic complex (EC) on performance, intestinal morphology and litter quality of 42-day-old broilers was evaluated. Seven hundred and fifty birds were used in a completely randomized design and 2 × 2 +1 factorial arrangement, with two MOS levels (0 and 0.1% from 1 to 21 days of age and 0.05% from 22 to 42 days of age), two EC levels (0 and 0.05%) and a diet with antibiotics (PC), totaling five treatments with five replicates. At 42 days of age, the performance was evaluated, and after slaughter, intestinal and litter samples were collected. MOS and/or EC inclusion did not affect the performance, perimeter and height of duodenal villi, crypt depth and villi density in duodenum, jejunum and ileum, and dry matter and total nitrogen content and pH of the litters. The MOS × EC interaction was significant to villi perimeter and height in jejunum, and birds submitted to diets without EC and with MOS showing higher values. The same behavior was observed to villi perimeter and height in ileum. However, when MOS and EC were added to diets, the values were lower for these variables. Ammonia volatilization increased in litter of broilers treated with antibiotics and decreased when MOS were added to diet. The inclusion of MOS and EC in the diets increased the villi perimeter and height in jejunum and ileum and decreased the ammonia volatilization of litters.
enzymes; intestinal morphology; prebiotic
