Effect Of Pre-freeze Addition Of Cysteine Hydrochloride And Reduced Glutathione On Post-thaw Sperm Parameters And Field Fertility In Jersey Crossbred Bull Semen

Abstract

The present 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 aged 4 to 6 years were used for the present study. A total of 36 ejaculates, 6 ejaculates from each bull (n=6) were collected and divided in to three groups, group I (control), group II (5mM cysteine hydrochloride) and group III (5mM GSH). The extended semen samples were added with @5mM additives, filled in mini straw using automatic filling and sealing machine (IMV, France) and cryopreserved in liquid nitrogen. Post-freeze seminal traits were also recorded after thawing at 37oC for 30 seconds. Post thaw livability was significantly (p< 0.01) higher in GSH group as compared to cysteine and control groups. The loss of acrosomal integrity was significantly (p< 0.01) lower in GSH group than cysteine and control groups. Analysis of variance for post thaw motility parameters (Forward progressive and Total motility) has revealed that significant difference (p< 0.05) between the good and poor freezer in the group II and there was no difference in the group I and III under study at 0 and 1 hr incubation period and at 2 hrs the group III and at 4 hrs group I has revealed significance difference (p< 0.05).The curvilinear velocity (VCL) and amplitude of lateral head displacement (ALH) values were significantly (P<0.05) higher in GSH than the cysteine and control groups. The Mitochondrial membrane potential (per cent) had no significance difference between the treatment groups. The present study indicates that the addition of cysteine and GSH suggestive of reducing lipid peroxide levels. The conception rate (%) in glutathione (68) added semen was significantly (p>0.05) higher than cysteine (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 VSL (r=0.7), loss of acrosomal integrity (r=-0.8) and mitochondrial membrane potential (r=0.9) had significant (p< 0.05) correlation with field fertility. The present study indicates that the use of glutathione as semen additives may be recommended for improving semen quality and overall augmentation of pregnancy in cows. The present study suggests that pre-freeze addition of glutathione was found to be better than cysteine in improving sperm fertility.