EFFECTS OF DIETARY BETA-CAROTENE AND RETI NYL-ACETATE ON BLOOD-RETINOID AND BETA-CAROTENE CONCENTRATION AND ON IN-VITRO OVARIAN-STEROID SECRETION IN JAPANESE-QUAIL

Laying quails (Coturnix coturnix japonica) were assigned to five group s according to the diet. Control group (K) was on basal diet (laying f eed, containing 9000 IU vitamin A/kg of feed). In treated groups, the basal diet was supplemented as follows: groups A1 and A2 with 10(5) an d 10(6) IU/kg retinyl-acetate; groups BC1 and BC2 with beta-carotene i n the rate of 10(2) and 10(3) mg/kg (Table 1) in the feed. At the end of the two week feeding period, 10 birds from each group were extermin ated. Blood samples were analyzed for retinol (Rol), retinol-palmitate (Ril-pal) and beta-carotene concentration. Granulosa cells from ovari an follicles (F1 and F2) were isolated and PMSG induced in vitro proge sterone (P4) secretion were measured. Similar retinol concentrations w ere found in both vitamin A and p-carotene supplemented groups, indica ting the saturation of the transporting system. High level of blood re tinol-palmitate, found in groups A1 and A2, could indicate subclinical hypervitaminosis, though beta-carotene concentrations of blood in the se groups decreased significantly. -carotene supplementation accompani ed by hypercarotenaemia, but did not increase the rate of retinyl-palm itate in the blood (Table 2). PMSG induced P4 production by granulosa cells were elevated in groups A1 and A2, but decreased significantly i n groups BC1 and BC2, both in dose-dependent manner.