Effect of pre-freeze addition of cysteine hydrochloride and reduced glutathione in semen of crossbred Jersey bulls on sperm parameters and conception rates.

This study was aimed to assess the effect of pre-freeze addition of cysteine hydrochloride and glutathione (GSH) on post-thaw sperm functional parameters and field fertility. The experimental bulls (n = 6) aged 4-6 years were used for this study. A total of 36 ejaculates (six ejaculates per bull) were collected and divided into three groups, group I (control), group II (5 mm cysteine hydrochloride) and group III (5 mm GSH). The extended semen samples with and without additives were filled in mini straw using automatic filling and sealing machine and cryopreserved in liquid nitrogen. Post-freeze seminal traits were recorded after thawing at 37°C for 30 s. The curvilinear velocity (VCL) and amplitude of lateral head displacement values were significantly (p < 0.05) higher in GSH than the cysteine and control groups. Post-thaw plasmalemma integrity was significantly (p < 0.01) higher in GSH group when compared to cysteine and control groups. The loss of acrosomal integrity was significantly (p < 0.01) lower in GSH than in cysteine and control groups. Addition of GSH non-significantly (p = 0.1) improved mitochondrial membrane potential (MMP) (per cent) than control group. This study indicates that the addition of cysteine and GSH suggestive (p = 0.08) of reducing lipid peroxide levels. The conception rate (%) in glutathione group was significantly (p < 0.05) higher than that in cysteine (68 vs 58) and control (49) groups. The post-thaw sperm progressive forward motility (r = 0.4) had moderate, but no significant correlation with conception rate. However, post-thaw straight-line velocity (r = 0.7), loss of acrosomal integrity (r = -0.8) and MMP (r = 0.9) had significant (p < 0.05) correlation with field fertility. This study indicates that the use of glutathione as semen additive may be used for improving post-thaw semen quality and overall augmentation of pregnancy in cows.

Attachment of spermatozoa to in vitro matured bovine oocytes in TCM-199 and MEM media.

Investigation was undertaken to study the efficacy of TCM 199 and MEM media in the process of oocyte maturation and fertilization after harvesting the oocytes from slaughtered cow and heifer ovaries by aspiration and mincing techniques. Out of 354 number of ovaries, mincing method could yield 1.35 (50.98%) of good quality oocytes per ovary as comparison to 0.61 (55.45%) by aspiration method. The TCM 199 and MEM could record the maturation of 85.71% and 60.26% of oocytes and the rate of sperm penetration was higher in TCM 199 matured oocytes (97.21%) as compared to MEM matured ones (74.46%). The staining of oocytes by aceto-orcein stain was also employed.