Date of Award:


Document Type:


Degree Name:

Master of Science (MS)


Animal, Dairy, and Veterinary Sciences

Committee Chair(s)

Jay W. Call


Jay W. Call


Doyle Johnson


During the last thirty years it has become increasingly apparent that pheromones play a major role in animal communication. Of economic interest to agriculturalists is the role pheromones play in signaling the state of estrus. The ability to efficiently detect estrus is becoming increasingly important, especially in the management of dairy and beef herds, where artificial insemination is used extensively. The understanding of pheromones may eventually provide a solution to this problem.

The purpose of this study was to identify one or more compounds in the urine of cattle which undergo a change in concentration during the estrous cycle.

In order to accomplish the objectives of this study, urine was obtained from cows exhibiting estrus and again 7 days post estrus. The urine was extracted with ether and the extract analyzed by gas chromatography. The area under each chromatographic peak was determined by integration. Areas were analyzed for variance between estrus and di-estrus. An attempt was made to identify each of the compounds represented by those peaks which proved to have statistically different concentrations . Two significant peaks were identified by coinjection with standards and found to represent propionic acid and iso-caproic acid. Three other statistically significant peaks were analyzed by mass spectrometry but concentrations were too low to determine the identities.

Results indicate that propionic acid, iso-caproic acid and two of the unidentified compounds decrease in concentration during estrus. The third unidentified compound was found to increase during estrus. studies have not yet been done to show pheromonal properties, however, the first step to allow such studies has now been accomplished. Five compounds have been found which change in concentration during estrus. Because the changes reflect similar concentration changes in pheromones, it is believed that they may eventually prove to be pheromonal.