Two body fluids containing bovine estrous pheromone(s)

Bovine females produce an estrous pheromone(s). Because onlyother cattle are reliable detectors of the pheromone(s), weevaluated various body fluids (cervico-vaginal mucus, serumand vulval skin gland secretion) with a bull behavioral assayin the absence of a female. It specified 15 behaviors involvingattraction to the body fluids, detection of the stimulus, andsubseqeunt sexual preparation responses. These behaviors werestereotypical and occurred in a specific sequence. We discoveredthat serum (10–15 ml) taken at estrus was behaviorallypositive, as well as vulval skin glands secretion (<1 mlon a swab, dissolved in 5 ml distilled water). We postulatethat vulval skin glands may be a specialized site for the productionor concentration of the pheromone or that the blood transportsthe pheromone(s) either from vulval skin glands or another source.