The Effect of Ovarian Laterality on Various Reproductive Parameters in Arabian Mares

Abstract

Objective: The present study aimed to investigate the effect of ovarian laterality on pregnancy outcomes and foal sex, and to explore the role of age and parity in determining the ovulation side in Arabian mares. Materials and Methods: Objective: The present study aimed to investigate the effect of ovarian laterality on pregnancy outcomes and foal sex, and to explore the role of age and parity in determining the ovulation side in Arabian mares. Material-Methods: Data were collected from 358 mares over a five-year period, during which 885 estrus cycles were monitored. The side of ovulation was determined using ultrasonography, and pregnancy was confirmed on days 14, 28, and 45 post ovulation. The mares were categorized into four age groups as 3-8, 9-13, 14-17, and ≥ 18 years. Results: The laterality of ovulation was evenly distributed between the right (49.3%) and left (50.7%) ovaries, with no significant difference in pregnancy outcomes between the two sides. The majority of pregnancies resulted from the first ovulation (51.9%), and pregnancy outcomes did not differ significantly among the ovulatory sequences. Likewise, no significant relationship was found between the ovulation side and foal sex. The distribution of ovulation sides was similar across the age groups; however, pregnancy rates declined with age. A significant relationship was observed between the age group and the ovulation side that resulted in pregnancy (p<0.05), with a general decline in pregnancies observed between the younger and older age groups on both sides of ovulation. Additionally, the parous state of the mares did not significantly influence the side of ovulation or pregnancy outcomes. Conclusion: Overall, in Arabian mares, ovarian laterality does not significantly influence pregnancy outcomes or foal sex and is not affected by parity or age, although a decrease in pregnancy rates with increasing mare age was evident. These results provide insights into the dynamics of ovarian laterality in Arabian mares and their impact on reproductive efficiency, which can guide the development of breeding strategies and assisted reproductive techniques.

Keywords

• Age
• Equine
• Foal sex
• Ovulation Side
• Pregnancy

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