Akademik Veri Yönetim Sistemi
Journal of the Hellenic Veterinary Medical Society, cilt.74, sa.2, ss.5537, 2023 (SCI-Expanded)
The present study aimed to investigate the effects of kisspeptin (Kiss-1), estradiol (E2), and progesterone (P4) concentrations at the time of artificial insemination (AI) on conception rates and whether or not there is a relationship between Kiss-1 and E2 concentrations in cattle. Cows (n=100) raised on a semi-open free-stall barn and having corpus luteum were intramuscularly injected 25 mg of prostaglandin F2α (5 mg Dinoprost, Dinolytic®, Zoetis, Spain) and signs of estrus were checked for 5 days after injection. The cows that did not show heat for 5 days following the PGF2α injection were injected with the second dose of PGF2α on the 7th day and the oestrus was checked for half an hour, 3 times a day for 72 hours. Just prior to AI, preovulatory follicle diameters were examined with transrectal ultrasonography and recorded. Then blood samples were collected. Blood serum samples were collected and stored until analyzed. Pregnancies were diagnosed with transrectal real time B-Mod ultrasonography on day 30±2 following AI. The mean follicular diameters at the time of AI were 17.82±0.01 mm. E2, P4, and Kiss-1 concentrations at the time of AI were determined in serum by ELISA. Mean concentrations of Kiss-1, estradiol and progesterone at the time of AI in all animals were 79.77±4.64 pg/mL, 117.09±1.48 pg/mL, and 0.61±0.02 ng/mL, respectively. The threshold value for kisspeptin, estradiol and progesterone concentrations were determined to be 82.03 pg/mL, 116.22 pg/mL and 0.93 ng/mL, respectively. Kiss-1 is a positive and significant predictor for the model but has limited accuracy. While Kiss-1, follicle diameter, milk yield, lactation period and AI number explains high accuracy (AUC=0.738) in pregnancy prediction, estrogen and progesterone are poor. In addition, a significant correlation was found between serum kiss-1 concentration and follicle diameter, whereas no significant correlation was found between follicle diameter and serum estrogen or progesterone concentrations. In conclusion, Kiss-1 was found to be limited accurate in predicting pregnancy in cows, whereas estradiol and progesterone were not.