Association between hormonal and structural changes of the reproductive tract in estrus dairy cows

AbstractNormal cyclic changes in hormonal and ultrasonic echotexture along with estrus are critical for successful breeding in dairy cows. We studied relationships among steroid hormone concentrations and ultrasound changes of uterus and ovaries just before insemination in heat dairy cows. Eighty-nine estrus dairy cows were selected for transrectal examination of uterus and ovaries, and blood sampling just before AI. Ultrasound characteristics of the uterus and ovarian structures were recorded. The concentration of estrogen, progesterone, and cortisol was measured in serum of estrus cows. Our results showed that there was not any relationship between ultrasound findings of uterus and steroid hormones in heat dairy cows. Also, there was no correlation between serum progesterone, estradiol, and cortisol concentrations with the diameter of dominant follicle. In addition, it was found that there was no correlation between serum progesterone, cortisol concentrations, and the presence of corpus luteum (CL) on ovary in heat cows, but there was a negative significant  relationship between the presence of CL and estradiol concentration (r = − 0.21,P = 0.04). Association between ultrasound characteristics of the uterus and steroid hormone (estradiol, progesterone, and cortisol) concentrations were not significant and considerable in estrus dairy cows.
Source: Comparative Clinical Pathology - Category: Pathology Source Type: research