Soybean meal is a widely used protein source in poultry nutrition, but its high global demand has prompted a search for alternative candidate ingredients. Insect products, like housefly larvae meal, have emerged as a promising sustainable option to partially replace soybean meal in monogastric diets. A total of 420 one-day-old (Ross 308) broiler chickens were used to evaluate the carryover effects of different levels (0.0, 1.5, 3.0, 4.5, and 6.0%) of dried housefly larvae (DHL) from 1 to 11 days on performance, blood serum traits, relative weight of gastrointestinal organs and carcass parts to body weight (%) and caecal microbial counts. All birds received a standard corn-SBM diet from 12 to 42d. Findings revealed that DHL produced from laying hen manure is a rich source of protein (58.69% CP), and its inclusion in broiler diets improved body weight and feed conversion ratio from 1 to 11 days of age. DHL did not negatively impact feed intake or the relative weight of gastrointestinal sections, but increased the caecal counts of Clostridia spp. and Lactobacillus spp. at 11 days, while Escherichia coli counts remained unchanged (P > 0.05). Serum total protein, and cholesterol levels at 11 d were not significantly influenced by DHL, but serum triglyceride (TG) content was reduced (P < 0.05). In conclusion, dried housefly larvae meal shows promising potential as a sustainable protein source in broiler chicken nutrition during the starter period. Further investigation is necessary to determine the optimal inclusion levels and its long-term effects on broiler performance and gut health.
