Abstract
Feed costs constitute a major portion of poultry production expenses, prompting interest in feed additives that enhance nutrient utilization. Proteases, as exogenous enzymes, have shown potential to improve protein digestibility and support the immature digestive systems of chick's birds. This study aimed to evaluate the effects of protease enzyme supplementation in broiler chicken diets, particularly in the context of Escherichia coli (E. coli) K88 challenge.
This study investigated the effects of supplemental exogenous protease enzyme on growth performance and gut microbiota of broiler chickens under a reduced protein-energy diet. A total of 200 broiler chicks one day age was allocated into four groups (T1–T4), each with 50 birds, and reared for 35 days. The experimental groups were fed different diets, T1 control group, T2 reduce protein – energy diets, T3 control with add 250g/ton of protease enzyme and T4 add 250 g/ton of protease enzyme supplementation to reduce protein – energy diets. Growth parameters including body weight (BW), weight gain (WG), feed intake (FI), and feed conversion ratio (FCR) were monitored, along with microbial analysis of drop E. coli and Lactobacillus counts.
The results indicated that protease supplementation of (T3 and T4) significantly improved final body weight (2169.02 g and 2186.81 g, respectively) and feed conversion ratio (1.45 and 1.46) compared to control (T1: 1895.7 g, FCR: 1.69). Feed intake was moderately increased in supplemented groups, reflecting improved nutrient utilization. Microbiological analysis showed a significant reduction in E. coli count and a highly significant increase in Lactobacillus populations in T4 compared to other groups (p < 0.001), indicating enhanced gut health.
In conclusion, dietary supplementation with exogenous protease enzyme can effectively improve growth performance and gut microbial balance in broilers fed low protein-energy diets, suggesting its beneficial role in sustainable poultry nutrition.