Abstract
The effects of increasing CM level in corn-animal protein-based diets and enzyme supplementation in broilers was investigated in a 30-day experiment. A total of 168, one-week old Cobb broilers were assigned to 8 diets consisting of 2 controls (with and without enzyme) and 6 other diets with 15, 30 and 45% CM levels with and without enzyme in a completely randomized design. Results showed significant interactions effects on growth parameters, fat digestibility, White Blood Cell (WBC) count, Saturated Fatty Acids (SFA) and Mono Unsaturated Fatty Acid (MUFA) (P < 0.05). Feed intake and WG were reduced on 30 and 45% diets (P < 0.05). Fat digestibility was improved on control and 30% CM diets with enzyme (P < 0.05). Higher WBC counts were recorded in control and 15% CM with enzyme (P < 0.05). Higher SFA and lower MUFA were on 15 and 45% diets (P < 0.05). In the main effects, feed intake and weight gain (WG) were reduced and feed conversion ratio (FCR) increased with increasing level of CM above 15% (P < 0.05). The diet with 45% CM showed lower SFA (P < 0.05) compared to 15% CM diet, MUFA and PUFA reduced with increasing CM levels (P < 0.05). Enzyme supplementation reduced SFA and MUFA content (P > 0.05) but improved crude fibre and fat digestibility of broilers (P < 0.05). In conclusion, 30% dietary CM inclusion is detrimental in terms of WG but has no effect on the fatty acid composition of broiler meat. More research into enzyme source and concentration above 30% CM is recommended.