Optimum inclusion and replacement value of boiled Mucuna cochinchinensis for soybean meal in broiler diets

Abstract

Optimum inclusion level of boiled Mucuna cochinchinensis and its replacement value for soybean meal in both starter and finisher broiler diets were assessed using 400 unsexed 7-day-old broiler chickens in a completely randomised experiment. The boiled Mucuna meal was used to replace soybean protein at five levels (0, 19, 38, 57 and 76%) in isonitrogenous and isocaloric diets. Feeding of the experimental diets lasted 4 weeks in each of the starter and finisher phases. During the last week of each phase, three birds per replicate were selected and used for metabolism (nutrient retention) studies. At the starter phase, only bodyweight and daily weight gain were significantly depressed (P < 0.05) by inclusion levels of 38% and above, whereas bodyweight, daily weight gain, feed conversion ratio and protein efficiency ratio were depressed (P < 0.05) by inclusion levels of 57 and 76% at the finisher phase. At both phases, the inclusion level had a cost sparing effect such that the highest inclusion level resulted in the production of the cheapest diet and lowest cost per unit weight gain. The replacement and inclusion levels produced no significant (P > 0.05) effects on the retention of all the proximate components and energy at both starter and finisher phases. Therefore, on the basis of bodyweight and weight gain, the replacement of soybean protein by boiled M. cochinchinensis at 19 and 38% for starter and finisher phases, respectively, is recommended. These translate to 9.36 and 14.4% inclusion levels of boiled M. cochinchinensis in starter and finisher broiler diets, respectively.