Cyclic changes in volatile constituents of bovine vaginal secretions

Headspace gas chromatography was used to examine the volatile components of bovine vaginal secretions in three consecutive estrous cycles from each of four cows. Results indicated that there was an interesting peak with a retention of 2.7 min. It showed a successive rise and fall zero to three days before estrus. Gas chromatographic evidence and mass spectral data confirmed that this peak was acetaldehyde. Another unidentified compound with a retention time of 27 min was found to be unique to proestrus. It occurred two to three days prior to estrus, but was absent at any other time of the cycle.     

Volatile fatty acids in urine and vaginal secretions of cows during reproductive cycle

Levels of volatile fatty acids (VFA) in vaginal secretions (VS) of cows were nearly independent of concentration changes of acids in the gastrointestinal tract, while levels in urine showed marked dependence. During three-week cycles, the VFA concentrations in VS increased shortly before heat and decreased to one third on days 19–22. Some cows showed an immediate increase after heat while in others the increase was slow and gradual. Moderately increased levels at midcycle were probably related to interovulatory follicle growth. Content of VFA in VS of pregnant cows was significantly above the level of the postestrus drop. Some pregnant cows in the first two thirds of gravidity had substantially higher levels of VFA than the other cows. Changes in VFA levels have a potential value for estrus detection and pregnancy diagnosis in cows. The gas chromatographic method used is too slow and tedious for practical application, but a reliable semiquantitative test for rapid proof of VFA or acetic acid in VS would be a very useful device for field use. It would have a substantial impact on the economy of cattle production by minimizing the loss of time due to delayed breeding.The results presented in this communication were presented in part in a dissertation submitted in partial fulfilment of requirements for C.Sc. degree (equivalent of Ph.D.) at the University of Veterinary Medicine, Brno, Czechoslovakia, in 1978.