Relationships among the cervical mucus urea and acetone, accuracy of insemination timing, and sperm survival in Holstein cows

The objectives of this study were to evaluate the relationships among urea and acetone content in cows’ cervical mucus (CM), its crystallization type (CT) and sperm survival (SS) after timed AI. Samples of CM were collected from 192 Holstein cows treated by Ovsynch® protocol. Analysis of the urea and acetone content for identification of the metabolic status, the arborization test for evaluation of insemination timing and the short-term heat test of SS for assessment of its suitability as a biological matrix were performed. The data set was analyzed by the GLM procedure using SAS®. The results documented the existence of substantial differences in individual response to the Ovsynch® protocol causing insemination of 55.2% cows at an inappropriate time. The urea content was found as a possible indicator of a cow's metabolism and/or of insemination timing, concentrations of less than 500mg/L corresponded (P5mg/L) negatively affected SS as well (P