Behavioural responses of pubertal Murrah buffalo heifers to bull bio-stimulation during the peri-oestrous period

Abstract This research paper aimed to determine if bio-stimulation affects peri-oestrous behavioural patterns of buffalo heifers and can improve oestrous behavioural responses through fenceline and direct contact with bulls during the heifers’ first and second oestrous cycles. Buffalo heifers are known to have poor and less intense expression of oestrus behaviour. This leads to lower oestrous detection rates and ultimately results in poor reproductive efficiency. Providing social cues, such as bio-stimulation, is an effective technique for improving oestrous behaviours in cattle, pigs and sheep. For this study, 24 pre-pubertal Murrah heifers were allotted to 3 groups of 8 each; similar in age (15.08 ± 0.16 months) and body weight (199.5 ± 0.21 kg). In T 0 , heifers were not exposed to a bull; in T 1 , heifers had continuous exposure to a bull behind a fenceline; and in T 2 , heifers were directly exposed to a bull twice daily (6 hours total). Oestrous behaviours were recorded on days −3, −2 and −1 (prior to oestrus), day 0 (day of oestrus) and on days +1, +2 and +3 (post-oestrus) using 24-hour digital cameras. Oestrous behaviours (sniffing/licking, tail raising, micturition, chin resting and mounting attempts) commenced on day −3 or day −2, peaked on day 0 and waned by day +2 or day +1 during both oestrous cycles. Oestrous behaviour frequencies were higher for the heifers in T 1 and T 2 groups ( P < 0.05) in comparison to the T 0 group during both cycles. Receptive standing in response to mounting was only observed during the second oestrous cycle on the day of oestrus, and the frequency was significantly highest in T 2 , followed by T 1 and T 0 ( P < 0.05). It was concluded that direct or fenceline bull exposure triggered more expression of oestrous behaviours in buffalo heifers, with direct exposure having a greater effect than fenceline exposure.