The Comparison Between Reproductive Performance in Synchronized and Spontaneous Estrus Sheep

Abstract

Purpose: The objective of the present study was to compare the reproductive performance in synchronized and spontaneous estrus sheep raised under farm conditions. Subjects and Method: Two hundred Karadi and Two hundred Awassi were used in this study. Of each breed, 100 ewes were allowed to come in estrus spontaneously and the other 100 ewes were synchronized using intravaginal sponges (ESPONJAVET, HIPRA, Amer, Girona, SPAIN). Ewes were injected with intramuscular injection of 500 IU of PMSG when sponges were removed on day 14. Results: This study revealed that estrus synchronization had a higher rate of lambing (P=0.014), twining (P<0.001), dystocia (P=0.024), and barrenness (P=0.012) in Karadi ewes. Estrus synchronization also had a significantly higher rate of lambing (P=0.018), twining (P=0.017), abortion (P<0.001), barrenness (P=0.012) and productivity (P=0.010) in Awassi ewes. the result of the current study shows that the barrenness rate was higher in spontaneously ovulated ewes compared to synchronized Awassi ewes. The result of the current study shows that the abortion rate was higher in spontaneous ewes compared to synchronized ewes. The twinning rate was higher in synchronized compared to spontaneous Karadi ewes. Conclusion: In both breeds, synchronized ewes had higher reproductive efficiency compared to ewes that had spontaneous estrus.