Levels of vitamin A supplementation for growing meat-type quails

Vitamin A is one of the fat-soluble vitamins that participates in metabolic processes of great importance and, as it is not enough produced by the body, it is essential to compose a diet. An experiment was carried the to determine the levels of vitamin A (Retinol) for meat quails (Coturnix coturnix sp), from 1 to 35 days of age, divided in two production periods, from 1 to 14 days and 15 to 35 days using seven different levels of vitamin A inclusion on the diets. Feed intake (FI) and accumulated body biomass (ABB) had linear effect while the body weight (BW), weight gain (WG), feed conversion (FC) showed a quadratic effect (P < 0.05) during the first period. The weight gain (WG) and accumulated body biomass (ABB) showed a quadratic effect (P < 0.05) for the second period, while the body weight (BW) increased linearly on the same phase. No significant differences were observed (P > 0.05) for hematocrit (HEM), the relative values of heterophils (H), lymphocytes (L), heterophil/lymphocyte ratio (H:L), serum enzymes aspartate aminotransferase (AST), alanine aminotransferase (ALT) and absolute liver weight (W liver). The absolute weight of Fabricius bursa (W bursa) showed a quadratic effect (P < 0.05), and absolute weight spleen (W spleen) was linearly influenced. In relation to the relative weight, only the spleen (Rw spleen) was influenced by the supplementation level of supplementation, it was observed that this supplementation has little effect on immunity of meat quails of 1–14 days old. The estimating levels of vitamin A were 3.35; 3.38 and 2.11 mg/kg to the period of 1 to 14 days and 2.82 and 2.67 mg/kg to the period of 15 to 35 days, respectively.