Effect of aspartyl protease in broiler chicken diets.

Introduction: Protein is one of the most expensive nutrients in balanced feed for production animals. Therefore, research on this topic seeks to reduce the economic impact on poultry farming. Objective: To evaluate the inclusion of protease produced by fermentation with Aspergillus niger in the feed of broiler chickens from 1 to 42 days, focusing on productive performance. Methods: The study was carried out at the Experimentation Unit in Palmira-Colombia, located in a thermally warm region at 1,000 meters above sea level. 960 one-day-old Cobb 500 chickens were used, grouped into 5 treatments: two control diets with a reduction in protein content by 3% (LP3) and 6% (LP6) of the birds' requirements and three diets with inclusion of protease (50, 100, 150 ppm) based on LP6, each with 8 repetitions of 24 animals per replicate, the productive performance of the birds was evaluated by analyzing live weight, feed consumption and conversion rate. Result and Discussion: When evaluating weight gain, it was observed that the birds that received the diets with 50 and 100 ppm of protease had a weight gain equal to the birds that received the diet with -3% protein, and greater than the birds that received the diet with -6% protein and those that received the diet with 150 ppm of protease. Regarding food consumption and weight gain, no differences were observed between treatments. The use of up to 100 ppm of protease in diets with 6% protein reduction can increase weight gain in broilers from 1 to 42 days, because proteases play an important role in physiological processes such as protein degradation, cell division and turnover, promoting intestinal health and reducing the colonization of pathogenic bacteria. Conclusion: Supplementing with serine protease at up to 100 ppm in diets with less than 6% protein improves weight gain of birds and can reduce production costs. [ABSTRACT FROM AUTHOR]