Abstract

The increasing demand for poultry meat has given rise to various stress factors. This study was aimed to investigate the effects of Bacillus subtilis and lysine in broiler birds under dexamethasone-tempted stress (DS). A total of 336-day-old broilers (Cobb 500) were assigned to seven sets (Probiotic @ 100 mg/kg of diet) on day 21 of trial; G1 (Negative control with basal diet), G2 (Positive control with basal diet and DS), G3 (DS+ Probiotic), G4 (DS+ low lysine; @ 5 g/kg of diet), G5 (DS+ Probiotic + low lysine; @ 5 g/kg of diet), G6 (DS+ high lysine; @11 g/kg of diet), G7 (DS+ Probiotic + high lysine; @11 g/kg of diet). For the stress, dexamethasone was presented to the fowls in drinking water; @ 3 mg/L daily from 21st to 28th day of the birds’ life. At 42nd day, two fowls from each replicate slaughtered for muscle and bone analysis. Supplementation of B. subtilis + high lysine (@11 g/kg of diet) significantly boosted the pH and histo-morphometrical parameters of muscle; diameter and cross section area of muscle fiber, diameter and cross section area of muscle fascicle with decline in drip loss compared with DS group (P < 0.05). Similarly, G7 showed significant elevation in the parameters of bone; weight, length, wall thickness, diameter, tibio-tarsal index and robusticity index in comparison with that of G2 (P < 0.05). In crux, B. subtilis + high lysine has a great potential to mitigate the negative effects of stress and improving health of broilers to get better yield economically.