Dietary substitution of soya bean meal with processed African yam bean meal as protein source in the diets of finisher broilers

Abstract

Considering the inherent attributes of processed African Yam bean meal (Sphenostylis stenocarpa), it's appropriate utilization for chicken diets may  enhance performance of finisher broilers. The study was therefore carried out to determine the dietary substitution of soybean meal with processed African yam bean meal as protein source in the diets of finisher broilers. The Processed African yam bean meal was used to substitute soya bean  meal at various levels to determine the best substitution that would give optimal performance in finisher broilers. The seeds of the African yam beans were soaked in water for 24 hours The soaked seeds were thereafter air dried for three days. The seeds were toasted for 35 minutes in a frying pan and milled using hammer mill. In the finisher feeding trial, the substitutions were 20%, 40%, 60% and 80% processed African yam bean  meal respectively. Each finisher diet was fed to a group of 30 broilers for 4 weeks using completely randomized design. Each treatment group was divided into 3 replicates of 10 broilers chicks each. The finisher broilers were kept in pens in deep litter and given feed and water ad libitum. The  parameters measured included initial body weight, final body weight, feed intake, body weight gain, feed conversion ratio, cost of production and carcass characteristics. The proximate composition of processed African yam bean meal showed that it contained 8.29% moisture, 91.71% Dry matter, 3.40% ash, 21.12% crude protein, 5% ether extract, 5.73% crude fiber and 56.4% nitrogen free extract. In the finisher feeding trial, the broiler  group on 40% processed AYBM significantly (P<0.05) recorded higher body weight gain than the rest of the treatments possibly because of the proper substitution of soya bean meal with processed AYBM in their diets and it appeared that the finisher broilers could tolerate high levels of  processed AYBM in their diets. The group on diet 2 (20% AYBM) and control diet recorded similar body weight gain (P>0.05) which were significantly (P<0.05) superior to the groups on diets 4 (60% AYBM) and 5(80% AYBM). The internal organs expressed as percent of the live weight were not affected by the treatments. Cost of production (cost/kg feed x feed conversion ratio) was lowest for diet 2 (N450.64) as against N480 for the control diet. The finisher broiler on diet 3 (40% AYBM) recorded the highest dressing out percentage of 78.78. The results of the trial have shown that processed African yam bean meal can be used to substitute soya bean meal in the diet up to 40% for optimum performance of the finisher broilers without affecting the body weight gain, feed intake, feed conversion ratio and carcass characteristics as indicated in this study.

Keywords: Dietary substitution, processed African yam bean meal, protein source, finisher broilers