author(s)
Prem Kumar R, Sunitha R, A Karthikeyan, Pradeep Kumar V and TG Honnappa

abstract
Besides genetic factors, environmental factors have significant effect on the quality of the semen that affects productivity of bulls. To determine seasonal effects on semen characteristics, 11,008 ejaculates collected from 25 Hallikar bulls were analyzed over a period of 15 years. The semen characteristics of Hallikar bulls was analyzed with respect to four seasons among the experimental period i.e. winter (January-February), summer (March-May), South-West monsoon (June-September) and North-East monsoon (October-December). Results revealed that season have significant (P<0.05) effect on spermiogram of Hallikar bulls but no significant seasonal variation on ejaculate volume, mass activity and post thaw motility of semen.