Growth Carcass Yield and Blood Profiles of Broiler Birds Fed High Fibre Diets Containing Different Levels of an Exogenous Enzyme.

Abstract

This experiment was conducted to investigate the effects of using Nutrizyme (an exogenous enzyme) on the performance of broilers fed high fibre diets. One hundred and forty four broiler chicks aged 7 days were divided into nine groups of sixteen birds each. Each group was replicated twice with eight birds per replicate which were assigned to nine experimental diets where spent grain replaced maize at 0, 6 and 12% at the starter phase and 0, 7 and 12% at the finisher phase. The diets were supplemented with Nutrizyme at 0, 0.5 and 0.8g/kg at both phases. A 3x3 factorial arrangement in a completely randomized design was used for the experiment which lasted 8 weeks during which Average Daily Weight Gain (ADWG), Average Daily Feed Intake (ADFI), Feed Conversion Ratio (FCR), Feed Cost per Kg Gain (FCKgG) and Carcass yield were measured while their blood profile was evaluated. Results showed that Nutrizyme supplementation of high fibre diets improved weight gain significantly (p<0.05) at the finisher phase. At the starter phase, weight gain, feed conversion ratio and average daily feed intake were not significantly (p>0.05) affected by enzyme supplementation. Feed cost per weight gain was positively significant (p<0.05) at the finisher phase, while carcass yield of finisher broilers were significantly improved by enzyme supplementation. Red blood cells, haemoglobin and total protein were significantly(p<0.05) higher with 0.5 and 0,8g/kg enzyme supplementation at the finisher phase but at the starter phase, blood profile of broiler birds were not significantly affected by enzyme supplementation. There was significant (p<0.05) interaction of nutrizyme and spent grain in ADWG, ADFI, FCR, and Carcass yield at 7% spent grain and 0.8g/kg enzyme levels at the finisher phase. It was concluded that enzyme supplementation at 0.8g/kg significantly improved weight gain over unsupplemented diets at 7% spent grain inclusion level at the finisher phase.