Effect Of Trehalose On Quality Of Cryopreserved Banas Kankrej Bull Semen

The present investigation on the “Effect of Trehalose on Quality of Cryopreserved Banas Kankrej Bull Semen” was undertaken at Dama semen production Unit, Banas dairy, Palanpur for a period of 12 weeks. Total three Banas Kankrej bulls aged between 4 to 5 years were used and semen was collected using artificial vagina method once weekly for twelve weeks from each of the bulls. The semen was evaluated for physical characteristics and enzymatic profile at post-dilution, post-equilibration and frozen thawed stages of cryopreservation using different Trehalose concentrations viz. 50mM Trehalose, 100mM Trehalose, 150mM Trehalose and control without Trehalose.          

Upon evaluation of 36 semen ejaculates (12 ejaculates from each bull), individual motility, sperm viability, sperm abnormality, osmotic resistance test (HOST) and acrosomal integrity were found to be 88.75 ± 0.25, 89.69 ± 0.32, 3.08 ± 0.15, 86.80 ± 0.24 and 90.72 ± 0.25 per cent, respectively. And the levels of oxidative stress parameters viz. lipid peroxidation and glutathione reductase were 49.96 ± 0.06 μmol/ml and 30.14 ± 0.06 U/L, respectively.

Correlation matrix revealed that all physical characteristics of semen had significant (P < 0.05) positive correlations among each other except the sperm abnormality which had inverse correlations. Malondialdehyde (μmol/ml) as well as glutathione reductase (U/L) had significant positive correlations with individual motility, sperm viability and acrosomal integrity.

At post-dilution, post-equilibration and post-thaw stages of cryopreservation, 100mM Trehalose group had individual motility as 84.58 ± 0.31, 75.00 ± 0.40 and 64.16 ± 0.52; sperm viability as 85.66 ± 0.46, 81.41 ± 0.28 and 71.41 ± 0.31; HOST reactive sperm as 83.25 ± 0.32, 78.16 ± 0.42 and 73.91 ± 0.35 and acrosomal integrity as 91.08 ± 0.41, 85.41 ± 0.39 and 80.91 ± 0.43 per cent, respectively and were significantly (P < 0.05) higher as compared to that of the 50mM Trehalose, 150mM Trehalose and control groups.

Mean per cent sperm abnormality in 100mM Trehalose group  were 4.67 ± 0.30, 6.34 ± 0.30 and 5.75 ± 0.35 at post-dilution, post-equilibration and post-thaw stages of cryopreservation, respectively and was significantly (P < 0.05) lower as compared to that of the 50mM Trehalose, 150mM Trehalose and control groups.

Mean Malondialdehyde (MDA) levels in 100mM Trehalose group were 43.92 ± 0.05, 34.20 ± 0.09 and 20.06 ± 0.13 μmol/ml at post-dilution, post-equilibration and post-thaw stages of cryopreservation, respectively and were significantly (P < 0.05) lower as compared to that of the 50mM Trehalose, 150mM Trehalose and control groups.

Mean glutathione reductase levels in 100mM Trehalose group were 55.83 ± 0.13, 64.00 ± 0.15 and 84.00 ± 0.16 U/L at post-dilution, post-equilibration and post-thaw stages of cryopreservation, respectively and was significantly (P < 0.05) higher as compared to that of the 50mM Trehalose, 150mM Trehalose and control groups.

Cryopreservation led to a significant (P < 0.05) decrease in semen quality parameters viz. individual motility, sperm viability, sperm abnormality, osmotic resistance test (HOST) and acrosomal integrity. Cryopreservation also led to a significant (P < 0.05) increase in Malondialdehyde (MDA) values and significant (P < 0.05) decrease in glutathione reductase (GSH) levels.

Conclusively, supplementation of 100mM Trehalose in the semen extender for cryopreservation was most appropriate concentration in view to preserve the semen quality in Banas Kankrej bull.