Occurrence of flehmen in male buffaloes (Bubalus bubalis) with special reference to estrus.

Pheromonal cues present in the urine and vaginal mucus during the estrus period elicit courtship behaviour in mammals including the characteristic flehmen behaviour. In the present study, the flehmen behaviour was assessed in male buffaloes by exposing them to heifers for three consecutive estrous cycles. Behavioural observations revealed that the bulls sniffed the female's external genitalia, responded to the chemical signal(s) and exhibited the flehmen behaviour similar to those reported in other ungulates. The flehmen behaviour was recorded daily during 15-min contact with females for three consecutive estrous cycles. Out of 180 observations during five days estrus periods (-3 to +1 days) which included high frequency of flehmen behaviour and out of 637 observations with or without flehmen behaviour during diestrus periods, the bull displayed 365 and 441 flehmen behaviour, respectively. Average numbers of all (2.03 +/- 0.66) and repeated flehmen (1.05 +/- 0.64) behaviour during estrus periods were significantly higher than those of diestrus periods of all (0.69 +/- 0.25) and repeated flehmen (0.11 +/- 0.10). The statistical significance was higher (P < 0.001) in repeated flehmen behaviour of estrus as compared to that in diestrus. In case of all flehmen behaviour, the statistical significance was higher (P < 0.01) in estrus when compared to that in diestrus. The occurrence of flehmen behaviour in male buffaloes clearly indicates that the specific pheromonal compound(s) present in the urine/vaginal mucus during estrus significantly influence the flehmen behaviour.