Factors affecting length of gestation in artificially inseminated Marwari mares of India

详细信息    查看全文

• 作者：Thirumala Rao Talluri¹ ; ^{raotalluri98@gmail.com} ; A. Arangasamy² ; J. Singh³ ; S.K. Ravi¹ ; Yash Pal⁴ ; R.A. Legha³ ; M. Alpha Raj⁵ ; Ashish Chopra⁶ ; R.K. Singh⁷ ; B.N. Tripathi⁸
• 关键词：Gestation length ; Mare ; Fetal gender ; Artificial insemination ; Breeding season ; Fetal birth weight
• 刊名：Asian Pacific Journal of Reproduction
• 出版年：2016
• 出版时间：November 2016
• 年：2016
• 卷：5
• 期：6
• 页码：481-489
• 全文大小：940 K
• 卷排序：5

文摘

To study the factors affecting length of gestation in foals from artificially inseminated Marwari mares for a period of ten consecutive breeding seasons.MethodsGestation length was measured in 126 pregnancies from which viable foals have born. Time of ovulation was confirmed through ovarian ultrasonography in order to determine true gestation length (ovulation to till foaling) as different to previous studies, in which either the mating to foaling interval or from fertilization to till parturition was used for calculating the gestational length. All the mares were inseminated artificially with frozen thawed stallion semen at appropriate time points by monitoring the point near to ovulation. Pregnancy was diagnosed approximately 11–15 d after ovulation initially, and re-affirmed at 30–60 d of pregnancy.ResultsThe observed mean gestation length for all the foals was recorded to be 342.20 ± 1.91 (with standard deviation 21.4) d, and ranged from 259 to 388 d. Various factors like parity of the mare, fetal gender, fetal birth weight, season of breeding (Artificial Insemination) and season of foaling were considered for their effect in causing variation on the gestation length in Marwari mares. According to the present study point of view and after compilation of the results, season of breeding and foal birth weight were found to show significant effect in causing true variation of the gestation length in Marwari horses. Other factors like sex of the foal and parity of the mare also had an effect on length of gestation, but whose effect was observed to be non-significant. Over the range of gestation lengths observed, season of foaling was not significantly associated either with gestational length of mare or foal birth weight.ConclusionFrom the current study it can be concluded that the true average gestation length for Marwari foals born is 344.1 ± 0.49 d. The range of gestation lengths was found to be 315–388 d all resulting in viable foals. The length of gestation is not significantly affected by age and parity of the mare. The only factors significantly affecting gestation length are foal gender and month of foaling (P < 0.05).