Behavioural Processes 67 (2004) 81–86
Flehmen response in bull: role of vaginal mucus and other
body fluids of bovine with special reference to estrus
R. Sankar, G. Archunan
∗
Department of Animal science, Bharathidasan University, Trichirappalli 620024, Tamil Nadu, India
Received 23 July 2003; received in revised form 13 February 2004; accepted 23 February 2004
Abstract
The present investigation was carried out with a view to evaluate the frequency of Flehmen behaviour in bull in response to
body fluids of cows in various stages of the estrous cycle, in the context of estrus detection. The study was performed on free
moving bulls under natural conditions. Samples of vaginal mucus, saliva, faeces and milk of pro-estrus, estrus and di-estrus
stages collected from donor cows were rubbed individually onto the genital regions of non-estrus animals (dummy cows) and
the bulls were observed for 30 min for assessment of Flehmen behaviour. The duration of Flehmen behaviour shown by bulls
was maximum towards the dummy cows receiving estrus sample. Such Flehmen behaviour, however, did not occur in bulls
in response to the cows receiving samples of other stages. The statistical significance was higher (P<0.001) in exhibiting
repeated Flehmen behaviour towards estrus as compared to those of pro-estrus and di-estrus. Among the various body fluids
tested, the exhibition of Flehmen behaviour was significantly higher (P<0.01) in response to estrus vaginal fluid. No response
was observed on dummy cows (control) to which only water was applied on the genital region. The results suggest that vaginal
mucus may act as an additional/secondary source along with urine in eliciting copulatary behaviour and executing coitus in bulls
during estrus. The results further suggest that in addition to vaginal mucus, other body fluids like saliva, faeces and milk have
estrus-related odours and are probably involved in bovine bio-communication.
© 2004 Elsevier B.V. All rights reserved.
Keywords: Bovine; Body fluids; Chemical signals; Estrus; Flehmen
1. Introduction
Chemical communication plays an important role
in mammalian sexual behaviour and reproductive pro-
cesses (Halpin, 1986; Dominic, 1991; Rekwot et al.,
2001; Archunan, 2003). It is well documented that
the female produces a specific odour during estrus
through vaginal discharge and urine which constitutes
∗
Corresponding author. Tel.: +91-4-312407040;
fax: +91-9-54312407045.
E-mail addresses: garchu56@yahoo.co.in,
garchu56@rediffmail.com (G. Archunan).
a major source for mammalian chemical communica-
tion. Widespread distribution of estrus-related odours
in other body fluids of some mammalian species, more
specifically, the cow have been reported (Kiddy et al.,
1984). For instance, sexually experienced males pre-
ferred the saliva of estrus females to that of non-estrus
females in Mongolian gerbils (Block et al., 1981).
It has been shown that the concentration of volatile
compounds in the faeces differed based on sex and
stage of the reproductive cycle and had a characteris-
tic chemical finger print (Kimura, 2001). The volatile
compound, ␥-12:2 lactone, identified in cow’s milk
was shown to be an active odorant (Bendall, 2001)
0376-6357/$ – see front matter © 2004 Elsevier B.V. All rights reserved.
doi:10.1016/j.beproc.2004.02.007