The experiment was conducted on 120 Karacabey Merino ewes divided into four groups. Two groups consisted of 2-year-old ewes, before their first lambing and two groups of the 3-year-old ewes after the first lambing. Within each age category, one group of ewes was treated with 5 ml 0.1% sodium selenate and 250 mg vitamin E, the other group progestagen sponge + 500 IU PMSG. The progestagen sponge + PMSG treated groups demonstrated oestrus symptoms earlier than the Vit E + Se injected groups. The progestagen sponge + PMSG treated group significantly increased fertility (100%, P < 0.01) and prolificacy (146.7%, P < 0.01) in 3 year-old ewes compared to other groups. The injections Vit E + Se significantly increased lamb birth weight (4.4 kg, P < 0.05) and daily weight gain for 60 days (290.0g, P < 0.01) in 3-year-old ewes compared with 2-year-old ewes treated with Vit E + Se and progestagen sponge + PMSG ewes.