Akademik Veri Yönetim Sistemi
Turkish Journal of Veterinary Research (Online), cilt.9, sa.1, ss.57-64, 2025 (TRDizin)
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: 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 ovulations. 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, 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. Younger mares had higher pregnancy rates, with left-side ovulation rates of 50.0% and 41.1% for
mares aged 3–8 and 9–13 years, respectively, compared to 13.9% and 5.3% for mares aged 14–17 years and
18 years and older. Similarly, right-side ovulation rates were 43.7% and 33.5% for younger mares, which
were higher than the rates of 11.0% and 1.3% for older mares. 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.