This study investigated the effect of Bakofix® (a supplement consisting of vitamin E, copper, zinc, manganese, cobalt, selenium, and calcium) on the reproductive performance of Anatolian Merino sheep. A total of 80 clinically healthy sheep were used in the study. They were synchronized with a progesterone-containing sponge outside the breeding season and divided into three groups. The first group (G1, n = 25) was administered Bakofix® treatment 7 days before estrus synchronization, the second group (G2, n = 25) was administered Bakofix® treatment when estrus synchronization began, and the third group served as the control (G3, n = 30). G1 showed a higher estrus response, conception rate, and pregnancy rate compared to the other groups. Particularly remarkable was the 84% pregnancy rate obtained in G1. The fecundity and litter size in G1 were 2.4 and 2.8, respectively, which were higher than those in the other groups. The multiple birth rate in G1 was significantly higher than that in G3, and Bakofix® treatment seven days before synchronization had a positive effect on the multiple birth rate, with a statistically significant difference between the two groups (P < 0.05). Although the multiple birth rate was high in G1, the birth weights of the lambs were not negatively affected. In conclusion, vitamin, mineral, and trace element supplementation can be applied to increase the reproductive performance of Anatolian Merino ewes, especially outside the breeding season and before estrus synchronization, which can lead to increased economic gain.