Prospects of using insects as alternative protein sources in broiler diets

Insects are garnering attention as promising protein sources for broiler diets, presenting nutritional and environmental benefits comparable to plant-based protein sources. Various insects have been explored as broiler feed ingredients, including mealworm (Tenebrio molitor and Zophobas morio), cricket (Gryllidae), grasshopper (Acrididae), black soldier fly larvae (Hermetia illucens), silkworm pupae (Lepidoptera), bloodworm (Chironomidae), and housefly maggot (Musca domestica Linnaeus). We reviewed the literature involving these insects to assess their impact on broiler diets. Previous research has indicated that supplementing broiler diets with mealworm larvae meal (0.3 to 1.0% inclusion level) improved growth performance. Black soldier fly larvae meal (2.0 to 5.0% inclusion level) can replace protein sources. Similarly, dietary supplementation with silkworm pupae meal (1.5 to 5.0% inclusion level) can also replace protein sources, while including dietary supplementation with housefly maggot meal (1.6 to 4.0% inclusion level) enhanced growth performance in broiler chickens. However, few studies have focused on the effects of dried crickets, dried grasshoppers, and bloodworm supplementation on broiler performance and health. Despite the limitation that insects are more expensive compared to soybean meal or fishmeal, the short breeding period and the high nutritional content of insects make their use in broiler diets generally promising. Our meta-analysis of 28 studies on black soldier fly larvae supplementation found that it significantly decreased average daily feed intake and increased average daily gain with an optimal level of 15.3% determined through quadratic regression analysis. In conclusion, supplementing broiler diets with different insects has potential as a strategy to enhance the growth performance of broiler chickens without compromising overall health.