Effects of Dietary Supplementation with Different Crop-Residue Biochars on Growth Performance, Carcass Characteristics and Internal Organ Proportions of Broiler Chickens
The increasing cost of conventional feed ingredients and the need for sustainable utilisation of agricultural residues have stimulated interest in alternative feed additives for poultry production. This study evaluated the effects of dietary supplementation with biochars produced from African breadfruit husk, soybean husk, Bambara nut husk and melon seed husk on growth performance, carcass characteristics and internal organ proportions of broiler chickens. A total of 150 day-old broiler chicks were randomly allocated to five dietary treatments in a completely randomised design, with three replicates of 10 birds per treatment. The control group received a basal diet without biochar, whereas the four experimental groups received the basal diet supplemented with 0.4% biochar derived from African breadfruit husk (ABHB), soybean husk (SBHB), Bambara nut husk (BNHB) or melon seed husk (MSHB), respectively. The feeding trial lasted eight weeks and was divided into starter and finisher phases. Body weight, body weight gain, average daily feed intake and feed conversion ratio were determined during each phase. At the end of the trial, carcass characteristics and relative weights of selected internal organs were evaluated. Treatment significantly affected initial and final body weight at some stages, whereas body weight gain, feed intake and feed conversion ratio were generally unaffected. At the finisher phase, birds fed the soybean husk biochar diet had the highest final body weight (2438.83 g), while birds receiving MSHB recorded the highest body weight gain (1011.90 g). Carcass weight differed among treatments, with MSHB producing the highest value (2342.66 g), while breast yield was highest in birds fed BNHB (30.43%). Abdominal fat was significantly higher in birds fed BNHB and MSHB than in the control group. Most internal organ proportions were not significantly affected by dietary treatment; however, relative spleen weight differed significantly, with the highest value recorded in MSHB-fed birds. Overall, dietary supplementation with 0.4% crop-residue biochars did not adversely affect growth performance or most carcass and organ characteristics. The findings indicate that low-level inclusion of crop-residue biochars may be feasible in broiler diets, although source-specific responses warrant further investigation. Future studies should characterise the physicochemical properties and contaminant profiles of the biochars and establish dose-response relationships before wider commercial application.
Keywords: biochar; crop residues; broiler chickens; growth performance; carcass characteristics; internal organs; sustainable feed additives.
