The investigation of the effects of vitamin A, vitamin E, and β-carotene plus vitamin E on some fertility parameters in ewes.

This study was aimed at investigating the effects of vitamin A (VITA), vitamin E (VITE), and combined β-carotene plus vitamin E (βCAR+VITE) injections on some fertility parameters in ewes. Estrus synchronization was performed by treating the ewes with intravaginal FGA sponges impregnated with 30 mg of fluorogestone acetate. On the days of the insertion and withdrawal of the intravaginal sponges, groups VITA, VITE, and βCAR+VITE were administered with 500 000 IU of vitamin A, 50 mg of vitamin E, and a combination of β-carotene plus vitamin E, respectively. The ewes in the control group (C) were maintained for control purposes. Statistically significant differences were determined between groups VITA and βCAR+VITE, groups VITE and βCAR+VITE, and groups C and βCAR+VITE, as well as groups VITE and C, groups VITA and C for the multiple birth rates. While significant differences were determined between groups VITA and C, groups VITE and C, and groups βCAR+VITE and C for the lambing rates, it was ascertained that the ratio of newborn lambs to delivered ewes (litter size) significantly differed between groups VITA and βCAR+VITE, groups VITA and C, groups VITE and βCAR+VITE, groups VITE and C, and groups βCAR+VITE and C. The highest MDA level and lowest GSH level were determined on day 20 after mating in the control group. In conclusion, it is suggested that both multiple birth rates and litter size can be increased by the combined administration of β-carotene and vitamin E.