Investigation of body secretions as bioindicators in cattle estrus detection

The accurate determination of estrus has a fundamental role in cattle reproduction management. The determination of volatile chemical compounds (pheromones) secreted only during estrus in all body fluids can be used for determining accurate estrus time and artificial insemination time and have a potential role in technological animal reproduction control. In this study, Holstein cows were synchronized and their sudor, urine, feces, milk, saliva, vaginal secretions, and blood samples were taken in the preestrus, estrus, and postestrus periods and analyzed by gas chromatography-mass spectrometry for determination of volatile odor compounds. A total of 531 volatile compounds were detected in the preestrus period, 538 in the estrus period, and 494 in the postestrus period. Among these, 8 compounds were found to be common in all body fluids and the ratio of these compounds to those detected in all body fluids was 2.6%. Especially in the estrus, 3-methyl pentane, hexanal, 4-methylphenol (p-cresol), phenylacetaldehyde, 3-phenylpropiononitrile, 1 H-indole, cyclotetrasiloxane octamethyl and pentane 2-methyl were detected. Biotechnology devices such as artificial nose with sensors can be developed, recognizing estrus-specific volatile compounds detected from all body fluids only in estrus period.