The pH of the bovine cervical mucus at estrus

Abstract

The pH of the bovine cervical mucus was determined with pH test strip introduced into the cervical canal immediately before insemination in the estrous stage. For 5 years, 82 of the 242 cases examined became pregnant. The pH in the estrous stage were distributed widely from pH 6.0 to pH 7.8. The cases with pH 6.8 were most frequent and then pH 6.6, pH 6.4 and pH 7.0 followed it in this order of frequency. The average of the pH values was pH 6.69±0.28. The pH of the mucus in which the cow became pregnant were distributed from pH 6.0 to pH 7.2. The cases with pH 6.8 and pH 6.6 were equally frequent and then pH 6.4 and pH 7.0 followed them. The average was pH 6.66 ±0.26.
According to the fiscal year or season, the pattern of the pH distribution showed some variation. However, the cases with pH 6.4 to pH 7.0 were always predominant. In relation to the age or the times of calving, the cases with pH 7.0 and pH 7.2 were relatively many in the heifers. There were found in relatively many cases in which the pH showed 6.6 after first to third times of parturition, and 6.4 above 4th parturition.