Abstract
This study was conducted to investigate the promotion of reproductive performance and economic indices performance of Zandi ewes under an accelerated lambing system (3 times lambing in two years). A total of 289 ewes from 3 to 4 years old, with mean body weight of 50 +/- 5 kg and BCS range from 2.5 to 3, were randomly allocated between two experimental groups as follow:1) in control group 98 ewes were exposed to rams all year-round without any hormonal treatment.2) in treatment group 191 ewes were exposed to rams 3 times in two years by means of hormonal treatment. In the second group ewes were treated with progesterone sponge for 14 days prior to the mating and received 400 IU of PMSG at sponge removal. Reproductive, productive and economic records of ewes were collected for two years and data were analyzed. According to the results, there were significant differences between treatment and control group in fecundity rate (249 vs.147%), prolificacy rate (264 vs.178%), lamb born crop (9.9 vs. 5.9 kg), weaning rate (206.28 vs.111.22%), fertility rate (198.95 vs.123.47%), parturition mean (2.11 vs.1.44 head) and lamb weaned crop (37.5 vs. 20.9 kg) respectively(P<0.05). By means of accelerated lambing method overall profits of the herd, based on the prices in the market in years 2013 and 2019, increased 18.36 and 45.52 dollars/ewe, respectively. The results of this study showed that zandi ewes have a good function in accelerated lambing system due to their specific physiological characteristics. According to the current conditions of Iranian economy, using this method to increase livestock profit is quite cost effective.