Influence of Osmolality of Complete Semen Extender on Motion Characteristics of Frozen-thawed Ram Spermatozoa

Abstract

The present study was conducted to observe the effect of osmolality of glycerolated TEST-yolk glycerol extenders on post-thawing sperm kinematics of ram spermatozoa of the native Malpura breed maintained in a semi-arid tropical environment. Good quality semen obtained from adult rams was pooled, split and diluted to 1,000 million spermatozoa per ml in complete TEST-yolkglycerol extenders of 900, 1,200, 1,500 and 1,800 mOsm/kg osmolality. Diluted semen samples were loaded in 0.25 ml straws and cooled down to -125°C freezing temperature at the rate of -25°C per minute under controlled conditions before plunging into liquid nitrogen for storage. The thawing of straws was performed at 50°C in a water bath for 10 seconds and sperm kinematics of the frozenthawed spermatozoa were assessed by a computer-assisted sperm analysis technique. Osmolality of diluent had no significant effect on post-thawing % motility, % rapid, % medium and % slow moving frozen-thawed spermatozoa but significantly (p< 0.05) affected the % linearity and % straightness.The post-thawing % motility and % rapid motile spermatozoa were highest in samples extended in diluent of 1,500 mOsm/kg osmolality and lowest in 900 mOsm/kg. The curvilinear velocity of spermatozoa was significantly (p<0.05) higher for samples extended in 1,800 mOsm/kg, compared to those in 900 and 1,200 mOsm/kg, but the effect was not significantly different to those extended in diluent of 1,500 mOsm/kg osmolality. The study indicated that ram spermatozoa could tolerate a wide osmolality range for dilution in the complete TEST-yolk-glycerol extender for their cryosurvival. The highest recovery of motile spermatozoa following thawing was achieved in samples extended in the TEST-yolk-glycerol diluent of 1,500 mOsm/kg osmolality.

Morphometric study of slaughtered Murrah buffalo bull testis and its correlation with seminal attributes of epididymal semen

“…(Thundathil et al, 2000) and buffalo (Sengupta and Bhela, 1988) but bull fertility hardly affected if abnormal spermatozoa do not exceed 15 to 20% (Pant et al, 2002). In the present study the increase of abnormality (percent) is mainly in the tail which suggests that osmolality change in the media may be responsible for this increase as suggested by Joshi et al (2006).…”

Effects of Sucrose and Glycerol during the Freezing Step of Cryopreservation on the Viability of Goat Spermatozoa

“…In agreement with our finding, Abdelhakeam et al (1991) reported that although maximum survival of ram spermatozoa before freezing was obtained with an isotonic extender, a hypertonic extender gave the highest post-thaw motility. Joshi et al (2006) found out that ram spermatozoa could tolerate a wide osmolality range for dilution. Also, these results agree with Fiser and Langford (1980) and Fiser et al (1982) who reported that hypertonic diluents are superior to isotonic diluents.…”

Ram sperm motility after intermittent scrotal insulation evaluated by manual and computer-assisted methods

“…We have no explanation for the observation that when comparing fresh and frozen/thawed semen from insulated and control rams, the percentages of MOT, PROG and RAP sperm fell more following freezing and thawing than ALH, VAP, VCL or VSL, when these changes were expressed as percentages of the prefreezing values, except to suggest that this treatment might http://www.asiaandro.com; aja@sibs.ac.cn affect those sperm with good motility less than those with poor motility, causing the latter to become completely immotile, therefore increasing the average velocities that are calculated only on motile sperm. Apart from a brief report [12] of reductions in percent MOT and RAP sperm and a decrease in VCL, VAP, VSL and ALH following freezing and thawing of ram semen, there seems to be little information on the quantitative changes in motility characteristics resulting from freezing and thawing of ram semen with which to compare the results of the present study.…”

“…By reducing the duration of the scrotal insulation, it was also hoped that a threshold effect would be produced, which might also reveal if there was much variation in the response of the testes of individual rams to heat stress. As additional ways of reducing sperm motility, we have used freezing or liquid storage of the semen, as both these procedures have been reported to cause changes in the motility characteristics of ram sperm [11,12].…”