Performance and carcass characteristics of Isa Brown cockerels fed graded levels of dried neem (Azadirachta indica) leaf and bark meal

The use of synthetic additives has some safety risks, residues, and consumer dissatisfaction. This has led Poultry farmers to prefer the rearing of healthy birds using natural growth and health-promoting natural feed additives. Azadirachta indica (neem leaf and bark) has good potential as feed additives. This study assessed the effect of graded levels of neem leaf and bark meal on the performance and carcass characteristics of ISA Brown cockerels. The study used two hundred and seventy (270) day-old ISA Brown strain cockerels. The birds were randomly allotted to nine dietary treatments of thirty birds each, replicated thrice with ten birds per replicate. The treatments were 0 g Neem leaf meal (NLM) and Neem bark meal (NBM) as control, 2.5 g, 5.0 g, 7.5 g, and 10.0 g NLM/kg feed-1, 2.5 g, 5.0 g, 7.5 g and 10.0 g NBM/kg-1 feed in a Completely Randomized Design. Birds were fed the experimental diets from 1st week to 20th week of age. Daily feed intake (DFI), Daily Weight Gain (WG), Feed Conversion Ratio (FCR), and carcass weight were evaluated. Data were analyzed using the General Linear Model at p = 0.05. Cockerel chickens fed 2.5 g/kg-1 NLM exhibited significantly higher Final Weight (FW), DWG, and ADG during the starter phase compared to the control. In the grower phase, birds fed 5.0 g/kg-1 Neem Bark Meal (NBM) showed significantly heavier FW, DWG, and ADG. Carcass features like wings, thighs, drumsticks, back, breast, head, and neck were similarly affected. At the finisher phase, neem bark meal up to 5.0 g/kg-1 of feed enhanced growth performance. Based on the outcomes of this study, the following conclusions can be drawn: Feeding cockerels with neem bark meal at a rate of up to 5.0 g/kg-1 of feed improved final body weight and resulted in a better feed conversion ratio. However, supplementation with 7.5 g/kg-1 neem leaf meal enhanced carcass characteristics in cockerel chickens.