Utilisation of Nile crocodile (Crocodylus niloticus) offal meal waste by-products as a novel protein substrate in the formulation of diets for Jumbo quail

This study evaluated the effects of incorporating full-fat crocodile offal meal (COM) in Jumbo quail diets as a replacement for soybean meal. A total of 256, one-week-old quail were assigned to 32 cages (8 birds/cage) in a completely randomized design, with eight replicates per treatment. Four diets were formulated: a control diet with no COM and three others containing 50 (COM5), 100 (COM10), and 150 g/kg COM (COM15). Body weight was recorded weekly, and daily feed intake was monitored to calculate the gain-to-feed ratio. At 5 weeks, post-slaughter measurements were taken. Weekly feed intake was significantly affected (P < 0.05), with COM15 having the lowest and COM5 the highest intake values (P < 0.001). COM5 yielded the greatest weight gain (P < 0.001) and higher survival rates (P < 0.001) compared to the other groups. Organ, breast, and thigh weights were generally higher in COM5. Symmetric dimethylarginine (SDMA) levels were elevated in the COM5 and COM15 diets (P < 0.05), while the Control showed lower SDMA. Feed digestibility, cholesterol, and water-holding capacity increased linearly (P < 0.05) with COM inclusion, while large intestine sizes decreased. Survival rates, organ weights, and muscle yields exhibited linear and quadratic trends (P < 0.05). Negative quadratic effects were observed for glucose and calcium, while positive ones were observed for haemoglobin and amylase. In conclusion, a 50 g/kg COM inclusion provided optimal results for quail performance, while higher levels negatively impacted outcomes, suggesting further research on COM inclusion levels.