Document Type : Research Paper

Authors

• Mahmood Sahraei ¹
• nader asadzadeh ²

¹ Animal Science Research Department, Ardabil Agricultural and Natural Resources Research and Education Center, AREEO, Ardabil, Iran.

² Animal Science Research Institute of Iran, Agricultural Research, Education and Extension Organization (AREEO), Karaj, Iran.

Abstract

The aim of this study was to improve the reproductive function of Moghani ewes in pasture conditions by using PMSG and GnRH following estrus synchronization. In experiment 1, at least 160 ewes were selected to perform the first step in the beginning of May. In this flock, four groups including control group (first), synchronization with progesterone sponge (second), synchronization with progesterone sponge plus injection of 400 IU PMSG on the day of sponge removal (thrid) and synchronization with progesterone sponge plus injection of 400 IU PMSG on the day of sponge removal and injection of 2 ml and Vitarolin (GnRH source) 50 hours after sponge removal(fourth). In the experiment 2, born lambs were fed by concentrate with 17.5% crude protein and 2.75 Mcal / kg metabolizable energy per kg of diet during suckling period for 90 days. The lowest lamb weight efficiency was obtained in the non-synchronized and hormone-treated (control) and progesterone-synchronized groups and the highest in the synchronized group plus the injection of 400 IU PMSG and 2 ml Vitarolin (P<0.05). The lowest yield of lamb birth weight was obtained in the first and second groups and the highest in the third group (P<0.05). In terms of weaning weight efficiency of lambs, the lowest amount was observed in the first and second groups and the highest in the third and fourth groups (P<0.05). In general, compared to the control treatment (first group), 60% more income was earned by the herdsman in the fourth group.

Keywords

• Estrus induction
• Reproduction
• Sheep

Main Subjects

• Animal and poultry physiology