Ovarian Inactivity in Dairy Cows: The Incidence, Causes and a Trial of Treatment

Abstract

The aim of the present study was to investigate the incidence and causes of ovarian inactvity and evaluate the efficacy of single administration of GnRH for treatment of inactive ovaries in dairy cows. Two experiments were carried out to fulfill the aims of the study. In experiment 1, 122 cows which had not shown estrous signs ≥ 45 after calving were examined twice by transrectal ultrasonography at a 7-10 day interval to diagnose the causes of anestrous and assess the incidence of ovarian inactivity. In Experiment 2, blood samples were collected from 30 cows with ovarian inactivity and 13 cyclic cows to comapre the blood concentration of insuline, glucose, calcium and phosphorus between the two types of cows. Cows (n=30) suffering from ovarian inactivity were treated with either 500 µg gonadorelin acetate intramuscular (G1; n=20) or saline intramuscular (G2; n=10). The ovaries of cows in G1 and G2 were examined by transrectal palpation twice before and twice after the treatment at a week interval. After transrectal palpation, blood samples were collected from cows for assessment of progesterone, insulin and glucose. Also the cows were observed for estrous signs and those cows showed estrus were inseminated. In Experiment 1, silent or unobserved estrus (47.5%), inactive ovaries (41%), cystic ovaries (9%) and pyometra (2.5%) were the reasons of anestrous in the Ovarian Inactivity In Dairy Cows: The Incidence, Causes ... A. Karen et., al.