Objective: The aim of this study was to evaluate the reproductive performance of the Arab mares in the Kingdom of Saudi Arabia (KSA).
Methods: Managers of 26 studfarms containing 1014 Arab mares at five districts were asked to complete a questionnaire on the reproductive efficiency of their mares.
Results: The mean age at first mating was 3.06 ± 0.5 years. Mares were mated equally in winter and all over the year. Natural mating was mostly used (76.9%). The means of estrus duration and estrus interval were 6.58 ± 1 days and 19.57 ± 1.8 days, respectively. The means of first service and over- all pregnancy rates and the number of cycles/pregnancy were 52.71 ± 20.2%, 83.72 ± 15.0%, and 1.46 ± 0.3, respectively, with no effect of the postpartum interval, district, or season. The average pregnancy duration was 335.5 ± 10.2 days. It was shorter in mares mated by day 9 postpartum than in those mated later (p < 0.05). The ratio of stallion/mares ranged from 1:4 to 1:24, with no correlation with the pregnancy rates or the number of cycles/pregnancy.
Discussion: Photoperiodic regulation and changes in the hypothalamic-hypophyseal axis of mares are usually associated with the seaso- nal reproductive activity of mares in the temperate but not in subtropical areas. Short duration of gestation for mares mated by day 9 after foaling may be related to the nutritional status of dams.
Conclusion: The obtained data represent the first record of the reproductive performance of Arab mares in the KSA, which could be used to anticipate their performance under different managements.
Clinical relevance: The Arab mares in the KSA are not seasonal and can reproduce efficiently all over the year. District and season did not influence the fertility.
Keywords: Reproduction; horse; pregnancy duration; pregnancy rate.