Effects of Different Holding Temperatures before Freezing on the Quality of Bull Semen

Abstract

A study was conducted to evaluate the effect of different holding temperature before freezing on the motility,
morphology and viability of chilled and frozen spermatozoa. Semen was performed from four mature bulls
by electro-ejaculator. After initial evaluation and first dilution using Tris-egg yolk semen extender, four
groups of diluted semen samples were kept in four different holding temperatures (4°C, 15°C, 25°C and
37°C) for 10 minutes. All semen samples were subsequently chilled in refrigerator at 4°C for at least 3
hours. Post chilling evaluation was done after second dilution with the same extender added with glycerol.
The semen samples were packed into 0.25 ml straws before freezing into liquid nitrogen. Thawing of frozen
semen samples were done on day 1 post cryopreservation in water maintained at 37°C for 30 seconds. Semen
evaluation was conducted post thawing. The results showed that there were no significant difference among
the four different holding temperatures for the post chilling and frozen-thawed sperm motility, morphology
and viability. Based on the findings of this study, it can be concluded that 10 minutes holding time at different
holding temperatures before freezing did not affect the quality of chilled and frozen bull spermatozoa.