Enzyme inclusion or fermentation of canola-based diets generate different responses in growth indicators, carcass quality, nutrient digestibility, bone strength, and blood biochemical parameters in broiler chickens

Abstract. This study aimed to evaluate the effects of dietary enzyme and fermentation supplementation on the growth performance, carcass traits, nutrient digestibility, and bone and blood characteristics of broiler chickens. A total of 900 male Hubbard broilers were assigned to three treatment groups: a control diet, fermented canola meal (6 %, 12 %, and 18 %), and enzyme-treated canola meal (6 %, 12 %, and 18 %). The results showed that both enzyme treatments resulted in superior weight gain, while 18 % fermentation supplementation had negative effects on weight gain and feed conversion ratio (FCR). Carcass traits, including dressing percentage and eviscerated weight, were significantly higher in enzyme-treated and fermented groups. Nutrient digestibility, particularly of crude protein and crude fiber, was improved with fermentation supplementation, with the best results being observed at 6 % and 12 % levels. Bone characteristics such as bone weight enhancement, robusticity index, and tibio-tarsal index were decreased (P<0.01) in fermented-diet-fed birds. Blood biochemical analysis revealed reduced triglyceride levels in broilers fed with a fermented diet, while other parameters, including cholesterol and glucose, remained unaffected. These findings suggest that optimal levels of fermentation and enzyme supplementation can enhance broiler productivity and health.