Formulation and proximate composition of basal diet.

1 Vitamin premix (g kg-1 premix): retinyl acetate (500 000 IU g-1), 2.40; cholecalciferol (500 000 IU g-1), 0.40; D,L-a-tocopherol acetate (50%), 12.54; menadione (23%) 0.79; thiamine nitrate (98%), 0.04; calcium-D-pantothenate (98%), 2.43; pyridoxine hydrochloride (98%), 0.59; cyanocobalamin (1%), 0.81; folic acid (9.6%), 0.40; niacin (99%), 2.17; D-biotin (2%), 4.91; mesoinositol (99%), 19.19; riboflavin (80%), 0.55; ascorhyl acetate (93%), 7.16. All ingredients were diluted with corn starch to 1 kg.
2 Mineral premix (g kg-1 premix): MgSO4·H2O, 56.200; FeSO4·H2O, 22.900; CuSO4·5H2O, 0.020; ZnSO4·H2O, 0.630; MnSO4·H2O, 1.650; KI, 0.070; NaSeO3, 0.004. All ingredients were diluted with corn starch to 1 kg.
3 Choline chloride premix (mg kg-1 premix): choline chloride was added to obtain graded levels of choline. The final choline concentrations in each experimental diet were determined to be197, 385, 770, 1082, 1436 and 1795 mg choline/kg diet, respectively.
4 Crude protein, crude lipid and total phosphorus contents were measured value.
5 Available phosphorus, n-3 and n-6 contents were calculated according to NRC (2011).
Formulation and proximate composition of basal diet.