Dietary inclusion of black soldier fly (Hermetia illucens) larvae meal improves growth metrics, carcass quality, nutrient digestibility, serum analytes and cecal microbiota in Japanese quail.

This study evaluated the effects of replacing soybean meal with black soldier fly (Hermetia illucens, BSF) larvae meal on growth performance, nutrient digestibility, carcass traits, serum metabolites, and cecal microbiota of Japanese quail. A total of 240 one-day-old quail were randomly assigned to four dietary treatments: a soybean-meal control (BSF0) and diets in which BSF meal replaced soybean meal at 10 % (BSF10), 15 % (BSF15), or 20 % (BSF20) of the ration. Birds were reared for 35 days in a completely randomized design with five replicates of 12 birds each and provided feed and water ad libitum. Quail fed BSF diets showed significantly greater feed intake, final body weight, total weight gain, and average daily gain than controls (P < 0.01), with the most efficient feed conversion observed at 15 % inclusion (P < 0.001). Carcass weight, yield, and breast/thigh proportions were also superior in BSF15 (P < 0.01). Dry matter, organic matter, and crude protein digestibility were highest in BSF15 birds (P < 0.01), while ether extract digestibility peaked in BSF10 (P < 0.001). Serum total protein, cholesterol, HDL, and LDL were unaffected, but triglycerides declined in all BSF groups (P < 0.05). Cecal counts of the tested bacteria were unchanged (P > 0.05). Feed efficiency was optimal at 15% inclusion. These findings indicate that partially defatted Black Soldier Fly (BSF) meal can replace up to 15% of dietary soybean meal in quail diets to improve growth performance, nutrient utilization, and carcass yield without adverse effects on blood metabolites or gut microbiota.