EFFECT OF NON-ENZYMATIC ANTIOXIDANTS IN EXTENDER ON POST-THAW QUALITY OF
BUFFALO(BUBALUS
BUBALIS)
BULL SPERMATOZOA
S. M. H. ANDRABI, M. S. ANSARI, N. ULLAH ANDM. AFZAL
Animal Reproduction Laboratory, Animal Sciences Institute,
National Agricultural Research Centre, Islamabad45500,
Pakistan
Abstract
The objective of the present study was to determine the effect of
non-enzymatic antioxidants (vitamin C or E) in tris-citric acid buffer (TCA) on
post-thaw quality of buffalo (Bubalus bubalis) bull spermatozoa. Split pooled buffalo bull
ejaculates were diluted in TCA egg yolk glycerol extender containing either
vitamin C (TCAC), vitamin E (TCAE) or without antioxidant (TCAN) at 37°C.
Extended semen was cooled to 4°C in 2 h and equilibrated
for 4 h at 4°C. Cooled semen was then
filled in 0.5 ml straws at 4°C and frozen in programmable cell freezer. Thawing of semen was
performed at 37°C for 30 seconds. Sperm motility, plasma membrane integrity and sperm
morphology (acrosome integrity, head, mid-piece and tail abnormalities) of each
semen sample were evaluated. Percentage of post-thaw spermatozoal motility assessed visually at 0 and
6 h and the post-thaw percentage of spermatozoa with intact plasma membranesat 0 h were higher (P<0.05) with TCAC and TCAE compared to control.
However, the differences in both these parameters between the former two groups
was non significant. The post-thaw percentage of spermatozoa with normal
acrosomes was higher (P<0.05) in TCAE extender than control. Mean sperm
abnormalities in samples cryopreserved with extender having TCAC, TCAE or TCAN
were similar (P>0.05). In conclusion, non-enzymatic antioxidants, particularly
vitamin E, in the tris citric acid extender
may improve the quality of frozen-thawed buffalo bull
spermatozoa.