Studies on the effect of hydrogen ion concentration of extender on semen characters of Murrah buffalo bulls

Abstract

The effect of semen extender Hydrogen Ion Concentration (pH) on seminal characteristics of 27 Murrah buffalo bulls
collected during the period from 1999 to 2001 were studied for Ejaculate volume, Initial motility, sperm concentration, pre-freezing
and post thaw motility, livability and sperm head, midpiece and tail abnormalities. The mean ejaculate volume, initial motility,
spem1 concentration, pre-freezing and post-freezing motility was 6.35±0.09 ml, 87.66±0.65%, 1146.42±21.65 (106/ml), 86.57±0.15%
and 64.80±0.'36%, respectively. The ejaculate volume was higher in winter and initial, pre and post thaw motility in summer.
Ejaculate volume and sperm concentration was lowest in summer. Effect of year and season of collection and the associated effect
of the age of the bull and the sperm concentration were not important in pre-freezing but had significant effect on post thaw
motility. The effect of bulls and extender pH groups and the associated effect of ejaculate volume and initial motility were needed
to be considered for pre-freezing while sperm concentration in postthaw motility. The mean live and dead sperm % were observed
to be 79.99±0.80 .and 19.88±0.8% respectively. The head, midpiece and tail abnormalities were 1.70±0.09, 0.19±0.03 and 3.79±0.15%,
respectively. Higher live sperms and lesser sperm abnormalities were observed when the pH of extender was between 6.7 to 6.8. The
correlations between initial, pre and post thaw motility for different seasons were calculated and were generally significant. It was
concluded that while freezing semen in Murrah buffaloe, the pH of extender should be between 6.7 to 6.8. The results also indicated
necessity of further studies on microclimate of semen during freezing and for existing methods of estimation of sperm concentration
to achieve higher post thaw motility.