Behavioral responses of bulls kept under artificial breeding conditions to compounds presented for olfaction, taste or with topical nasal application

The objective of this study was to test practical ways of influencing the sexual behavior of bulls used for artificial insemination. Dairy bulls that were sexually active with regular semen collections were compared with sexually inactive bulls housed elsewhere, after being sampled in artificial breeding as yearlings. The behavior of bulls in response to various volatile compounds and mixtures was recorded. These behaviors included sniffing, licking of sample, tongue manipulation, vocalization and flehmen. Single compounds found as volatile compounds in estrous blood did not evoke appreciable responses. Mixtures of these compounds evoked some response, but the most powerful stimulus was urine collected from teaser bulls. Most sexually active and inactive bulls responded quickly to urine soaked cloths brought near them. They would attempt to reach the urine sample, sniff it and lick it, followed usually by a strong flehmen. Sexually active bulls while in their familiar semen collection area with mount bulls paid little attention to the urine as compared with licking the teaser bulls. Thus, with this visual stimulus the effect of olfaction stimulus on sexual arousal of dairy bulls was minimal.