Akademik Veri Yönetim Sistemi
Indian Journal of Animal Research, cilt.59, sa.8, ss.1303-1309, 2025 (SCI-Expanded)
Background: For high fertility in mares, it is important to have one foal a year and to have foaling early in the season, especially in racehorse breeders. Therefore, the fertility achieved by breeding the mare in foal heat is the determining factor. However, compared to thoroughbreds, there is not enough research on fertility results from postpartum breedings, such as foal and subsequent heats in Arabian mares. Thus this study aims to evaluate the fertility following the foal heat or subsequent postpartum breedings in Arabian mares. Methods: In this study, in 184 mares (aged 4 to 25 yr), a total of 240 postpartum first breeding cycles (foal heat or subsequent heat), including 12 mares with three, 26 mares with two cycles and 152 mares had one cycle, were evaluated. The ultrasonograhic examinations were done to determine follicle diameter at the breeding day, pregnancy and pregnancy loss on days 14, 28 and 45 following breeding. In addition, live foal rates were also recorded. Mann-Whitney U and Chi-square tests were used to compare continuous and categorical data, respectively. The factors affecting breeding were analysed by logistic regression analysis and ROC analysis was used to calculate threshold values for the day of postpartum breeding and the follicle size at breeding. Result: The per cent of mares were bred during their foal heat was 73%, while 27% were bred during their subsequent heat. The pregnancy rates for the mares bred at foal heat (56.8%, 100/176) and at subsequent heat (60.9%, 39/64) had no significant differences in between. Also, the pregnancy loss for the mares bred at foal heat and at subsequent heat were not significantly different, with 10.0% (10/100) and 2.6% (1/39), respectively. The live foal rate was also similar for the mares bred at foal (44.6%) and susequent heat (51.6%). It was found that the day of breeding (being earlier/at or later than 11 days pp) had significant effect on pregnancy (p=0.035) and pregnancy loss (p=0.025). In addition, live foal rates were effected by the day of breeding (p=0.017) and the size of the follicle (smaller or equal/greater than 47 mm) on the day of breeding (p=0.026). It was concluded that breeding a mare after the 10th day postpartum, along with a follicle diameter exceeding 47 mm on the day of breeding, has the potential to indicate achievable fertility for foal heat. Thus, it could be beneficial to taking these criteria into account in the postpartum reproductive management of Arabian mare.