Evidence Based Approach for Midcycle Estrum in a Crossbred Jersey Cows

Background: Effective and correct estrus detection determines the successful Artificial Insemination (AI) and in turn acceptable performance in dairy cows. All cows presented with estrus signs for AI are not usually fit for breeding for which mid cycle estrum (MCE) is one of the major causes that must be ruled out to prevent unnecessary AI and thereby preventing economic loss to the farmer. Methods: The present study was designed to compare reproductive parameters of True Estrum (TE) and MCE in crossbred Jersey cows. Around 24 cows addressed for AI has been randomly selected for the study. Based on history, clinical signs and ultrasonographic examination the cows were divided into two groups TE (n=12) and MCE (n=12) and assessed for their qualitative and quantitative parameters. Result: No significant difference could be observed between TE and MCE cows in expression of estrus signs. The size of the corpus luteum (CL) was significantly larger in MCE cows. In conclusion, no ovulation will occur in MCE cows, hence cows addressing with estrus signs needs to be ruled out for prominent CL ( greater than 15 mm) and relaxation of cervical internal os before AI.