Pregnancy rates according to follicle diameter and uterus edema in different age groups in two consecutive ovulations in Arabian mares

Abstract

The study aimed to evaluate the pregnancy rates of mares in different age groups based on follicle diameter and uterine edema during two consecutive ovulations in three breeding seasons. Thirty Arabian mares were divided into two groups: below and equal to 10 years (Group A=54) and above 10 years old (Group B=36). Throughout the breeding season, the diameters of ovulatory follicles and uterine edema were recorded. After the first ovulation, when the follicle diameters of all mares in both Group A and Group B were analyzed independently of age, and compared between pregnant and non-pregnant mares, no differences were found (P>0.05). The differences between the agerelated groups were insignificant (P>0.05). Follicle diameters between pregnant and non-pregnant mares at the second ovulation were significantly different (P0.05). Differences between uterine edema values determined in mares that were pregnant and nonpregnant in two consecutive ovulations were found to be insignificant in terms of pregnancy (P>0.05). As a result, although preovulatory diameter is not a reliable marker for pregnancy detection, it remains an important parameter for determining ovulation and artificial insemination timing. Uterine edema is only useful for determining the timing of insemination and is not associated with pregnancy. Moreover, since similar pregnancy rates were observed among different age groups, age alone is not a sufficient parameter for assessing reproductive efficiency in mares.