The present study was conducted to explore the season and parity effect on acoustic features of vocal signals articulatedn by Murrah buffaloes during estrous cycle. Voice and blood samples were collected from healthy Murrah buffaloes (n=60), maintained at ICAR-NDRI, Karnal. Animals were classified into three groups heifers (n=20), primiparous (n=20), pluriparousn (n=20) and further each group (20) was classified into two sub groups (n=10) based on winter (September-February) and summer (March-July) season. The acoustic features were extracted by the help of PRAAT 5.1.36 software package. The features like call duration (sec), intensity (mean, maximum, minimum) (dB), formants (Hz): F1, F2, F3, F4, F5, jitter (%), shimmer (%) and N/H ratio (%) were found statistically (P<0.05) different during estrus phase. The season effect especially during estrus phase was found significant (P<0.05) for minimum intensity (dB), F1 (Hz), F3 (Hz), and jitter (%). There was significant (P<0.05) difference between heifer and pluriparous buffaloes for intensity (dB) (mean, maximum, minimum), F1-F5 (Hz) and jitter (%). Significant differences were found for E2 (pg/ml) and P4 (ng/ml) plasma levels among four phases of cycle and between both seasons. This study concluded that hot season and parity cause variations in acoustic features like intensity, frequency and formants due to fluctuation in steroid hormones levels and summer stress. So, season and age factor might be considered for further determination of threshold values especially for estrus phase to develop algorithm/DSS for efficient and automatic estrus detection in buffaloes.

Highlights

• Need of animal friendly heat detection method for accurate identification of heat in buffalo.
• Vocal signatures-based acoustic features variation for estrus detection in buffalo.