Tinospora cordifolia modulates the seminal parameters, leakage of intracellular enzymes and seminal antioxidants in equilibrated and cryopreserved semen of Sahiwal bulls.

The present study was undertaken to assess the effects of stem extract of Tinospora cordifolia (Giloy or Guduchi) in the semen extender on seminal parameters, leakage of intracellular enzymes and antioxidants in semen of Sahiwal bull. A total of 48 ejaculates from four bulls were selected for the study. Spermatozoa of 25 × 106 were incubated in 100, 300 and 500 µg of stem extract of Guduchi as Gr II, III and IV, respectively, and pre-freeze and post-thaw semen samples were analysed for seminal parameters [motility, viability, total sperm abnormality (TSA), plasma membrane integrity (PMI) and acrosomal integrity (AcI)], intracellular enzymes [aspartate aminotransferase (AST) and lactate dehydrogenase (LDH)] and seminal antioxidants [superoxide dismutase (SOD) and catalase] in comparison with an untreated control group (Gr I). The results revealed that stem extract-treated semen had significantly (p < .05) higher motility, viability, PMI, AcI, SOD and catalase and had significantly (p < .05) lower TSA, AST and LDH compared to those in untreated control group at pre-freeze and post-thaw stages. Semen treated with 100 µg stem extract/25 × 106 spermatozoa had significantly (p < .05) higher motility, viability, PMI, AcI, SOD and catalase and had significantly (p < .05) lower TSA, AST and LDH compared to those in control, 300- and 500-µg-treated groups at pre-freeze and post-thaw stages. Further, these seminal parameters and antioxidants were showing decreasing trend and TSA and leakage of intracellular enzymes were showing increasing trend from Gr II to Gr IV at pre-freeze and post-thaw stages. Thus, 100 µg/25 × 106 spermatozoa were optimum or suitable dose for cryopreservation of Sahiwal bull semen. The study concluded that T. cordifolia stem extract 100 µg/25 × 106 spermatozoa in the semen extender can be effectively utilized to reduce the oxidative stress and improve the pre-freeze and post-thaw seminal parameters in Sahiwal bull. However, further studies on effects of different concentrations of stem extract on in vitro or in vivo fertility trials are to be conducted to assess the impact of the stem extract supplementation in the semen extender on field pregnancy outcomes in bovine species.

Seasonal variation in heat shock proteins (hsp70 and hsp90) and their association with frozen semen quality and fertility in buffaloes.

BACKGROUND: Heat shock protein is considered as a potential indicator of animal adaptation to harsh environmental stresses and its expression has been correlated with resistance to stress. OBJECTIVE: To evaluate the seasonal variation in heat shock proteins (hsp70 and hsp90) and their association with frozen semen quality and fertility in buffaloes. MATERIALS AND METHODS: During summer and winter, ejaculates (n = 32) were collected from buffalo bulls, diluted with freshly prepared Andromed extender (maintained at 34 degree C) up to 80 million sperm per mL. The diluted semen was filled in French midi straws, equilibrated, and cryopreserved. The semen was evaluated at pre-freeze and post-thaw stages for heat shock proteins (HSP70 and HSP90), and sperm quality parameters. RESULTS: The levels of HSP70 were significantly (P = 0.00) higher in summer season compared to winter season. The HSP70 had a positive correlation with mass motility (P <0.05; r = 0.39), live sperm count (P < 0.05; r = 0.47), and acrosomal integrity (P < 0.05; r = 0.37). The first artificial insemination conception rate (FAICR) had a positive correlation with HSP70 (P < 0.05; r = 0.47), and HSP90 (P < 0.05; r = 0.59), in frozen-thawed semen. CONCLUSION: The assessment of the levels of heat shock proteins may help in predicting cryo-tolerance and fertility of buffalo semen during various seasons.

Effects of dietary supplementation with omega-3 fatty acid-rich linseed on the reproductive performance of ewes in subtropical climates.

The present study evaluated the effects of omega-3 (ω-3) fatty acid-rich linseed supplementation on the reproductive performance, endocrine profile, and biochemical profile of ewes reared in subtropical climates. Forty-eight acyclic and clinically healthy Marwari sheep, aged 1.5-2.5 years with no parity, were divided into four groups (n = n = 12 in each). Ewes in the control group (group I) were fed only a basal feed, whereas ewes in the treatment groups II, III, and IV were fed the basal diet along with 10%, 15%, and 20% linseed, respectively, daily on a dry matter basis. The experiment was conducted during the typical breeding season (October-November) of the sheep. The estrus induction rate was significantly higher (p < 0.05) in all treatment groups than in the control group. The estrus induction interval was significantly lower (p < 0.05) in group III. The conception rate in group I was significantly lower (p < 0.05). In addition, ewes in the control group had a significantly lower (p < 0.05) lambing rate than all treatment groups. Serum progesterone concentrations differed significantly (p < 0.05) between the control and the treatment groups on days 15, 30, 45, and 60 of supplementation. On treatment days 15 and 30, the serum estrogen concentrations were significantly higher (p < 0.05) in all treatment groups compared to that in group I. In all treatment groups, monounsaturated fatty acid (MUFA) decreased significantly (p < 0.05), whereas polyunsaturated fatty acid (PUFA) increased significantly (p < 0.05) from day 15 onward. In conclusion, by providing 15% dietary linseed supplementation to ewes, their reproductive performance can be improved in subtropical climates. Future studies are recommended to further elucidate the role of linseed supplementation in sheep reproduction in subtropical climates.

Enriching membrane cholesterol improves stability and cryosurvival of buffalo spermatozoa.

Buffalo spermatozoa are comparatively more susceptible to freezing hazards than cattle spermatozoa. In recent times incubation of spermatozoa with cholesterol-loaded-cyclodextrins (CLC) has shown improvements in semen quality in several species. Therefore, this study was undertaken to evaluate the incubation level of CLC at which maximum benefit is derived for the buffalo spermatozoa. For the study, 120 million spermatozoa were incubated in 2, 3 and 4 mg/mL of CLC (Gr II, III and IV, respectively) and cholesterol and phospholipids content, their ratio, flow cytometric evaluation of plasma membrane integrity (PMI), plasma membrane fluidity and extent of cryoinjury (Chlortetracycline, CTC assay) were compared with an untreated control (Gr I). Additionally the ability of cholesterol-loaded-spermatozoa to undergo induced acrosome reaction (IAR) using ionophore calcium (A23187) was evaluated in frozen-thaw samples. Data show a significant and linear increase (CV=0.88) in cholesterol content of spermatozoa in Gr II, III and IV and a significant decrease in phospholipids content at frozen-thaw stage in Gr IV than Gr III spermatozoa. The study revealed a significant improvement in PMI and significant reduction in plasma membrane fluidity and cryoinjury of CLC treated spermatozoa at progressive stages in three groups compared to control. Nevertheless, spermatozoa of Gr II, III and IV were significantly less responsive to ionophore calcium (A23187) than Gr I. This study shows for the first time that incubation of buffalo bull spermatozoa with CLC (3mg/120×10(6)) prior to processing permits greater numbers of sperm to survive cryopreservation while allowing spermatozoa to capacitate and the acrosome to react to AR inducer ionophore calcium (A23187).