Seasonal Variation in Sexual Behaviour of Deoni (Bos indicus) Bulls

Background: Sexual behaviour is an intricate process, controlled by the endocrine constitution of an animal and influenced by the social environment, sensory capability and sexual stimuli. Variations in temperature associated with global warming are startling for fertility of animals. The objective of the present study was to assess the seasonal variation in sexual behaviour of Deoni (Bos indicus) breeding bulls. Methods: A total of six mature Deoni bulls, maintained for artificial insemination at Livestock Research Center, Southern Regional Station of ICAR-NDRI, Bengaluru, were monitored for sexual behavior during the semen collection at weekly intervals throughout the year using standard techniques. The period of study was divided into three seasons i.e., winter (November to February), summer (March to June) and rainy (July to October). Result: The season had a non-significant (P greater than 0.05) effect on sexual behavior except dismounting time in Deoni bulls. The libido score (0-10), reaction time (seconds) and the total time taken in mounting (seconds) were non-significantly (P greater than 0.05) higher during winter (7.50±0.23, 42.00±4.8, 44.00±4.8, respectively) as compared to the other seasons. The protrusion score (0-4) and the intensity of thrust (0-4) were non-significantly (P greater than 0.05) higher during summer (2.60±0.14 and 2.50±0.13) as compared to the other seasons. The dismounting time (seconds) was significantly (P less than 0.05) higher during summer (2.90±0.16) as compared to the other seasons. It can be concluded that Deoni bulls had good sexual behavior throughout the year, however, bulls showed better sexual behavior except for dismounting time during winter as compared to the other seasons.