Effects of Fermented Fish Waste and Meat-bone Scraps on Laying Performance and Profitability in Japanese Quail

Calcium is essential for quail growth and eggshell formation, but commercial sources are expensive. The present study aimed to evaluate fermented fish waste (FW) and meat and bone scraps (MBS) as alternative calcium sources for Japanese quail, examining their effects on growth, reproduction, egg production and quality, and economic returns. A total of 240 female quail (120 ± 10 g at 35 days post-hatch) were randomly allocated to eight dietary treatments (n = 30) in a randomized complete block design with three replications (10 quails each), comprising a formulated calcium-deficient diet (0.8% Ca of dry matter [DM]), a standard layer diet (3.0% Ca DM), and six calcium-supplemented diets using fermented substrates (50 or 100 mL/kg, sprayed onto basal feed). The feeding trial lasted 85 days and evaluated growth performance, reproductive and productive traits, egg quality, and profitability. Mineral analysis of the fermented substrates showed that MBS contained significantly higher calcium than FW (14.86 versus 11.12 mg/kg), while phosphorus and iron levels were comparable. Growth performance differed significantly among treatments at 70 (mid-lay) and 120 (peak production) days post-hatch, with 50 mL MBS/kg producing the highest body weights (180.28 g at 70 days; 229.48 g at 120 days). Reproductive traits (age at first egg, age at sexual maturity, and body weight at maturity) were unaffected by dietary treatments. Production performance and egg quality improved significantly with calcium supplementation compared to the calcium-deficient control. At 120 days, 50 mL MBS yielded the highest hen-day production (96.82%), egg weight (10.83 g), and egg mass (41.94 g) compared to all other treatments, including the standard diet. Shell thickness and albumen height with 50 mL MBS significantly exceeded those of the calcium-deficient diet and matched or surpassed those of the standard diet at both measurement times. Economic analysis showed the highest return on investment for 50 mL MBS (68.69%), comparable to the standard diet (66.06%). These results demonstrate that 50 mL/kg fermented MBS provides a practical, sustainable, and cost-effective calcium source for laying quail, achieving optimal performance across growth, production, egg quality, and economic parameters under the conditions tested. Keywords: Bone scrap, Calcium supplementation, Circular economy, Egg production, Egg quality, Fermented fish waste, Japanese quail