While the size of the preovulatory follicle is a crucial marker of reproductive potential in mares, its connection to reproductive parameters, especially in Arabian mares, remains uncertain. This study examined the association between preovulatory follicle size and various reproductive parameters in 301 Arabian mares, monitored ultrasonographically over four years and 563 estrous cycles. The mares were categorized into four age groups: 3–8, 9–13, 14–17, and 18 years and older. The preovulatory follicle diameter across consecutive cycles and the size of follicles leading to pregnancy post-ovulation were analyzed in relation to the ovulation side, age, parity, ovulatory cycle, and parous state. The mean preovulatory follicle size was 46.3±4.34 mm (range: 39–60 mm), with no significant difference between the pregnancy and non-pregnancy cycles (p=0.490). Parity was not correlated with overall follicle size (r=-0.013, p=0.757) or follicle size during the pregnancy cycles (r=-0.060, p=0.303). However, preovulatory follicle diameter varied significantly across ovulatory cycles (p=0.040), with the second cycle having the smallest mean follicle size (45.45±0.35 mm) compared to the first (46.5±0.23 mm) and third (46.95±0.53 mm) cycles. Additionally, parous mares had significantly larger follicles (46.40±0.19 mm) than maiden mares (45.25±0.57 mm, p=0.050), while age group (p=0.796) and ovulation side (p=0.558) had no significant effect on follicle size. Follicle size remained consistent between pregnancy and non-pregnancy cycles across different age groups, consecutive cycles, parity states, and ovulation sides. These findings suggest that although follicle size varies across ovulatory cycles and parous states, it does not significantly affect pregnancy outcomes in Arabian mares. This insight could help refine breeding strategies by emphasizing the role of factors other than follicle size in optimizing reproductive success.

Peganum harmala L. (Zygophyllaceae) known locally as harmel is a medicinal plant. In traditional medicine, its seeds have long been used for therapeutic purposes because of their richness in β-carboline alkaloids. This study aimed to evaluate the maternal and developmental toxicity during pregnancy by daily IP administration of 7.99 mg/kg/day (1/20 DL50) of total alkaloids extract in P.harmala’ seeds. The results summarized in confirmed pregnancy rates were high 90-100%, decreased locomotor activity, paralysis, and hypothermia. Maternal body weight and weight gain changes were statistically significant in all pregnant. Precisely, the relative weight of ovaries was significantly changed in all the groups treated. The ALAT and gamma GT concentrations show a significant change in the group treated for seven days. Significant changes in the total and indirect bilirubin levels were observed in all treated groups. The hormonal analysis showed a significant decrease in FSH levels in a treated group for seven days and two weeks, Progesterone levels were increased significantly in treated groups for seven and three weeks and increased significantly in a treated group for two groups, however, the levels of Estrogen were changed significantly only in the treated group for three. The results show a significant difference in total resorbed litters and the number of fetus deaths in the group treated for three weeks. The fetus weight in the group treated for two weeks was significant. The results show a significant decrease in the number of implantations and an increase in pre-and post-implantation loss rates, and there were no developed live or dead, and no resorbed fetuses in all treated dams, there were only implantation sites in both uterine horns. The total extract of the alkaloids in the seeds of P. harmala has adverse effects on maternotoxicity, embryonic development, and abortion.