Reproductive hormones associated with normal and abnormal changes in ovarian follicles in postpartum dairy cows.

摘要: Abstract Concentrations of reproductive hormones and ovarian changes were monitored every 4 days during the postpartum period in 35 dairy cows. The cows classified as either control (22 cows) or cystic (13 based on per rectum examination ovaries. Control detected with a corpus luteum after first ovulation while cows, follicles at least 2.5cm diameter persisted absence for 14 days. mean interval to follicle 1.5 2.0cm was about 16 both groups. Ovulation earlier group (18.4±1.7 days) than (36.3±2.7 days). Luteinizing hormone plasma increased early (days 1 10) groups, but concentrations luteinizing hormone, progesterone, estradiol-17 β not different between groups then −8, −4, 0 (day diameter). During this −8 0), correlated positively, regression coefficients differed These results suggest partial hypothalamic and/or pituitary failure releasing cause cysts.