In a randomized design trial, the effect of adding a multi-enzyme (ME) to a wheat and barley (W+B) diet on performance was studied using 1125 day old broilers. Five replicate groups of 25 birds were assigned to each of nine treatments. The isocaloric and isonitrogeneous treatments consisted of: 1) W+B diet supplemented with the ME from day 0 to 7, 2) same as 1, but the ME was supplemented to 14-d, 3) same as 1, but the ME supplemented to 21-d, 4) same as 1, but the ME was supplemented to 28-d, 5) same as 1, but the ME was supplemented to 35-d, 6) same as 1, but the ME was supplemented to 42-d, 7) same as 1, but ME was supplemented to 49-d, 8) as one, but no ME added, and 9) corn and soy diet. Water and mash diets (0 to 28 and 29 to 49-d) were provided ad-lib throughout the study. Body weight and feed intakes were taken weekly on a pen basis and the litter samples form each pen were taken only on day 49. Mortality and cull birds were weighed and recorded daily. Birds fed the corn-soy diet showed higher body weight trough out the study followed by treatment 7, but this difference was only statistically significant compared with treatments1, 2 and 8 (P<0.05). There was clearly a linear response to the weight gain in response to the ME addition over the time. However, feed efficiency was not improved over the time of ME supplemented diets. Birds that received diet 4 had better feed efficiency (1.86) than the treatments 9, 8, 2 and 1 (P<0.05). Contrary to our expectation FE was slightly better for the treatment 4 than 7, but this was not statistically significant (P>.05). As expected, birds which fed diet 8 had poorest feed efficiency (2.02) and highest mortality than all other treatments (P<0.05). The litter pH was lowest for treatment 7 and highest in treatment 9. The pH content of the litter was reduced in response to enzyme addition over time. The litter moisture was lowest in treatment 7 and as anticipated highest for treatment 8. In conclusion, our finding suggests that more research is needed to learn how to maximize the beneficial and economical effects of enzymes, over the inclusion time, in broiler performance. Key Words: Multi-Enzyme, Performance, Wheat and Barley
