Impact of Manipulating Quail Eggs with Betaine During Early Embryogenesis on Chick Development, Hatchability, Hematological Variables, and Some Physiological Estimates

Abstract This study evaluated the effect of spraying incubated quail eggs with betaine on chick development, hatchability and some physiological estimates of Japanese quails during early embryogenesis. A total of 750 eggs were equally divided into two groups (2 groups × 5 treatments × 5 replicates × 15 eggs). Eggs in the 1st group were incubated at normal incubation temperature (37.5°C/NIT), while those in the 2nd group were incubated at chronic incubation temperature (39.5 °C/CIT) for 3 hours daily from the 4th up to and 6th day of incubation. Eggs in NIT and CIT groups were subjected to five treatments, T1 (negative control), T2 sprayed distilled water (positive control), while T3, T4, T5 groups sprayed distilled water supplemented with 500, 1000 and 2000mg betaine/L respectively. The chick weight at hatch and slaughter weight and first egg weight was significantly impaired by CIT treatment. CIT group revealed a significant increase in the H/L ratio and a significant decrease in T3 hormone and blood protein levels than the NIT group. Regarding betaine effects, the embryonic mortality rates, hatchability, hatched chick weight, and slaughter weight were significantly improved compared with the control. Also, betaine significantly increased blood protein and T3 hormone levels and significantly decrease the liver enzymes levels and total feed consumption compared with untreated group. The RV/TV ratio of quails in CIT group was significantly increased, while betaine treatment significantly decreased this ratio. Considering these results, it’s strongly suggested that spraying of betaine on eggs at 1000 or 2000 mg//L optimizes Japanese quails performance.