Effects of Enzyme Supplementation on the Utilization of Sweet Potato (Ipomoea batatas) Meal Based Diets by Broiler Chickens

Abstract

A feeding trial was conducted to determine the effects and optimum levels of replacing maize with sun-dried sweet potato meal supplemented with a multi-enzyme (SDSPM+EZ) in broiler chicken diets. Four isonitrogenous and isocaloric broiler starter and finisher diets were formulated to replace maize at graded levels of 0, 25, 50 and 75 percent. The starter and finisher diets were fed to three replicate groups of birds for four weeks during each phase. Eighteen and fifteen chicks per replicate were assigned during the two phases respectively in a complete randomized design. In the first phase, chicks fed 25% SDSPM+EZ diet had significantly the best (P<0.05) final body weight (786.80g), daily weight gain (26.71g) and FCR (2.27). Performance was also better for the 50% SDSPM+EZ treatment compared to the control group. There were no significant differences in the feed consumption of the birds with up to 50% SDSPM+EZ replacement of maize. Feed cost (N/kg gain) for birds on all SDSPM+EZ diets were lower than for the control group. During the finisher phase, final body weight, daily weight gain, FCR and feed cost (N/kg gain) improved significantly with increasing level of SDSPM+EZ up to 50% maize replacement. At 75% SDSPM+EZ performance was adversely affected. Weight of carcass and breast cut were significantly higher for the 50% and 25% SDSPM+EZ treatment groups. Trend analysis gave optimum replacement levels of 37.5% and 52.50% SDSPM+EZ for maize in starter and finisher diets. It was concluded that up to 50% of maize in broiler chicken diets can be replaced by SDSPM+EZ with satisfactory performance.

Keywords: Broiler chicken, Maize, Multi-enzyme, Sun-dried sweet potato meal, Optimum levels