Comparative Effects of Bacillus subtilis Probiotic and Abutilon indicum Leaf Powder on Growth Performance, Nutrient Digestibility, Antioxidant Status, and Carcass Traits of Broiler Chickens

Abstract

The search for viable, non-antibiotic alternatives in poultry nutrition has intensified focus on both microbial and phytogenic feed additives to optimize gut health and production efficiency. This study evaluated the comparative effects of Bacillus subtilis probiotic (Gallipro Max) and Abutilon indicum leaf powder (AILP) on the growth performance, nutrient digestibility, antioxidant status, and carcass traits of Ross 307 broiler chickens. A 42-day feeding trial was conducted using 500 one-day-old broiler chicks randomly assigned to 5 dietary treatments (n=100 birds/treatment), with each treatment subdivided into 5 replicates of 20 birds each under a completely randomized design (CRD). Treatment 1 (T1) was fed a basal control diet alone; T2 received the basal diet supplemented with Gallipro Max at 200 g/kg; while T3, T4, and T5 were fed the basal diet supplemented with AILP at 100, 200, and 300 g/kg, respectively. Final body weight, feed intake, carcass yield, and dressing percentage were lowest in T1, intermediate in T3 –T4, and significantly higher in T2 and T5. Feed conversion ratio (FCR) was optimized in T2 and T5 and poorest in T1. Mortality was exclusively recorded in T1, whereas all sup-plemented groups (T2 –T5) recorded 100% survival rates. Relative weights of high-value cuts (breast, thigh, leg, shank) and gizzard were significantly increased in T2 and T5, while liver, heart, spleen and kidney weights showed no significant variations across all groups (P>0.05). Apparent nutrient digestibility coefficients for dry matter, crude protein, crude fat, crude fiber, and ash were substantially enhanced in T2–T5 compared to the control. Physiologically, dietary supplemen-tation significantly reduced malondialdehyde (MDA) levels while concurrently boosting serum immunoglobulins (IgG, IgA, IgM) and endogenous antioxidant enzymes (catalase, superoxide dismutase, glutathione peroxidase) in T2 –T5 relative to T1. In conclusion both Bacillus subtilis probiotic at 200 g/kg and Abutilon indicum leaf powder at 300 g/kg serve as potent, safe bio-enhancers. They maximize broiler growth, tissue accretion, and nutrient digestibility while simultaneously reinforcing systemic antioxidant status and humoral immunity.