Investigating the effect of stress factors on pregnant Zandi ewes and physical characteristics of newborn lambs

The present study was conducted to investigate the effect of stressors on ewes during pregnancy and the physical characteristics of newborn lambs. To perform the experiment, 144 Zandi ewes with twin embryos were divided into 6 treatments and 6 replications (each replication containing 4 ewes) that were mid-pregnant. Experimental treatments include 1. Control, 2. Injection of cortisol in 10 times, 3. Isolation in 2 times (2 times isolation), 4. Isolation in 10 times (10 times isolation), 5. Simulated wool cut in 10 times and 6. Wool cut in mid-pregnancy. The results showed that the ewes treated with cut wool during lactation had a significant increase in weight compared to the ewes of the group 2 times isolated, 10 times isolated and the simulated cut wool (P <0.05). Sheared wool ewes had greater body condition compared to ewes in the simulated wool cut and cortisol group (P <0.05). Lambs born in the control and wool cut groups had longer body length compared to the lambs in the other groups (P <0.05). The amount of cortisol in ewes that received cortisol and also, wool was cut, there was a significant increase with the control (P <0.05). Lambs born from ewes that had their wool cut had a higher live weight (P <0.05). In general, the results showed that although stresses during pregnancy increase the concentration of glucocorticoids, but their concentration by wool cutting during pregnancy was such that it did not reduce the weight characteristics of ewes and lambs