Effect of concentration and addition method of glycerol on the quality of cryopreserved mithun (Bos frontalis ) spermatozoa

Flaxseed oil modulates semen production and its quality profiles, freezability, testicular biometrics and endocrinological profiles in mithun

Mithun (Bos frontalis) is a unique domestic free range bovine species of North Eastern Hilly (NEH) regions of India. Effect of feed supplementation of Flaxseed oil (FSO) on semen production and its quality profiles, freezability, oxidative stress, apoptotic sperm percentage and subsequently on endocrinological profiles & scrotal and testicular biometrics in different seasons was studied in mithun. The experimental animals were divided into two groups, Gr I: Control (n = 3) and Gr II: Treatment (n = 3; Flaxseed oil @ 150 mL/day). FSO was supplemented through oral drench in the morning hours just before concentrate feeding. A total of 80 semen samples (n = 80; 20 semen samples from each season; each 10 semen samples from control and treatment groups per season) were collected, not more than twice per week in winter, spring, autumn and summer seasons. Semen quality profiles (SQPs) such as volume, sperm concentration, motility (forward progressive and total), motility & velocity profiles by computer assisted sperm analyser (CASA), viability, total sperm abnormality, acrosome integrity, plasma membrane & nuclear abnormality and apoptotic sperm percentage were estimated in fresh semen. Along with SQPs measured in fresh semen, motility in estrus bovine cervical mucus (bovine cervical mucus penetration test; BCMPT) and mitochondrial membrane potential (MMP) by JC-1 stain were determined in the post-thawed semen samples. Biochemical profiles (aspartate aminotransferase; AST, alanine aminotransferase; ALT, total cholesterol; CHO), antioxidant profiles (superoxide dismutase; SOD, catalase; CAT, glutathione; GSH, total antioxidant capacity; TAC) and oxidative stress profile (malondialdehyde; MDA) were estimated in fresh semen whereas AST, ALT, lactate dehydrogenase (LDH), TAC and MDA were estimated in the frozen thawed semen samples. Endocrinological profiles such as follicle stimulating hormone (FSH), luteinizing hormone (LH), testosterone, cortisol and thyroxin and scrotal circumference (SC) & testicular biometrics were measured in both groups in different seasons. Result revealed a significant (p < 0.05) improvement in motility (total & forward progressive, motility & velocity by CASA and vanguard distance in cervical mucus), viability, intactness of acrosome & plasma membrane, MMP, antioxidant profiles and reduction in total sperm and nuclear abnormalities, reduction in leakage of intracellular enzymes and reduction in oxidative stress profile and reduction of apoptotic sperm percentage were observed in FSO supplemented than in un-supplemented control group accordingly in fresh and post thawed semen samples. Blood FSH, LH, testosterone and thyroxin concentration were significantly (p < 0.05) increased and cortisol concentration was significantly (p < 0.05) decreased in FSO supplemented group than in unsupplemented control group. Similarly, SC and testicular biometrics were increased significantly (p < 0.05) in supplemented than unsupplemented group for different seasons and significantly (p < 0.05) higher in winter and spring than in summer season in the experimental groups. It can be concluded from the study that supplementation of FSO can effectively be utilized to improve the antioxidant profiles, reduction of oxidative stress with cascading beneficial effects on SQPs and fertility status of the mithun bull.

Strong Heterogeneity in Advances in Cryopreservation Techniques in the Mammalian Orders

Between 1970 and 2012, vertebrate abundance has declined by 58% with an average annual decline of 2%, calling for serious action to prevent a mass extinction and an irreversible loss of biodiversity. Cryobanks and cryopreservation have the potential to assist and improve ex situ and in situ conservation strategies by storing valuable genetic material. A great deal of studies concerning cryopreservation have been performed within the class Mammalia, although no systematic overview has previously been presented. The objective of this study is therefore to evaluate the status, pattern and future of cryopreservation within Mammalia. A strong disproportional distribution of studies in examined orders is displayed. For the majority of examined orders less than 10% of species has been examined. However, the cryopreservation of germplasm has in several cases been successful and resulted in successful applications of assisted reproductive techniques (ARTs). Various obstacles are associated with the development of cryopreservation protocols, and among them the most prominent is interspecific differences in cryotolerance. Extrapolation of protocols in closely related species is considered the most applicable procedure, and a future supplement to overcome this problem is the examination and comparison of cryobiological traits. Successful protocols have been developed for the vast majority of domesticated mammals, which gives incentive for the further extrapolation of protocols in threatened species.

Administration of slow release exogenous melatonin modulates oxidative stress profiles and in vitro fertilizing ability of the cryopreserved mithun (Bos frontalis) spermatozoa

Mithun (Bos frontalis) is a unique domestic free range bovine species of North Eastern hilly regions of India. The present study was designed to assess the seasonal effect of slow release exogenous melatonin (MT) implant on semen quality parameters (SQP) and in vitro zona binding ability (IVZ) of spermatozoa. The experimental animals were divided into Gr I: Control (n = 5) and Gr II: Treatment (n = 5; melatonin implant @ 18mg/50 kg bwt). A total of 20 semen samples/group in winter, spring, autumn and summer seasons (n = 160), twice per week were collected. Following cryopreservation, samples were evaluated for motility parameters (forward progressive, mobility & velocity by computer assisted sperm analyser (CASA), viability, acrosome integrity, plasma membrane and nuclear abnormality, functional status of mitochondria, enzymatic, antioxidant and oxidative profiles, and IVZ. The study revealed significant (p < 0.05) improvement in total motility, viability, acrosome-, plasma membrane-, and nuclear-integrity, and antioxidant profiles; with highest values in spring and lowest in summer season in the fresh semen in Gr II than the Control. A significant (p < 0.05) improvement in motility parameters, membrane potential of mitochondria, antioxidant profiles and reduction in sperm and nuclear abnormalities, leakage of intracellular enzymes and oxidative stress and IVZ index & binding percentage in post-thaw semen samples in melatonin supplemented than in un-supplemented control group was observed. It can be concluded from the study that slow-release melatonin supplementation can be effectively utilized to improve the antioxidant profiles and reduction of oxidative stress, with cascading beneficial effects on semen quality parameters and fertility status of the mithun bull.