ABSTRACT
Two experiments were carried out to determine the levels of supplementation of inorganic selenium (Se) and vitamin E (VE) in diets of quails aged 0-14 and 14-35 days old. A completely randomized design was used in a factorial design (Se = 0.1125; 0.2250; 0.3375 and 0.4500 mg kg-1 diet-1 × VE = 10; 23; 36 and 49 IU kg-1 diet-1 ). In experiment 1, quail (n = 2,400) were aged 0-14 days and were divided into 16 treatments, with three replicates of 50 birds. In experiment 2, quail (n = 1,680) were aged 14-35 days and were divided into the same treatments, with three replicates of 35 birds. At age 0-14 days, the levels of VE did not affect performance (p > .05); however, the feed conversion (FC) was influenced by a quadratic effect (p = .0515), according to the level of Se, with a higher level estimated at 0.29 mg Se kg-1 diet-1 . At age 14-35 days, there was a linear effect with interaction (Se × VE), for FC (p = .0150) and weight gain (WG; p = .0266). FC (Se, p = .0048 and VE, p = .0019) and WG (Se, p = .0049 and VE, p = .0068) improved linearly with increasing levels of Se and VE. The feed intake (FI) decreased linearly (p = .0582) as a function of VE. The carcass yield showed a quadratic effect (p = .0056) on the levels of VE, with a higher yield estimation of 27.24 IU VE/kg of diet. It can be concluded that the optimum level of supplementation at age 0-14 days was 0.29 mg Se kg-1 diet-1 and 10 IU VE kg-1 diet-1 and at age 14-35 days, it was 0.4500 mg Se kg-1 diet-1 and 49 IU of VE kg-1 diet-1 .
