Daily and seasonal rhythmic secretary pattern of endocrinological profiles in mithun bull.

Mithun (Bos frontalis) is a unique domestic free-range bovine species available in North Eastern hilly (NEH) regions of India and is reared for its protein rich meat. Mithun suffers severe non-cyclical population fluctuations; however, it is not yet declared as endangered species. Mithun follows some sort of seasonality based on the calving trend and semen production, although it is a perennial breeder. However, there is need to study the rhythmic changes of endocrine profiles to understand the hormone flow pattern in mithun to select the suitable time for blood collection to assess the exact endocrine profiles and to select the suitable time for natural breeding or semen collection by artificial methods for further research, conservation and propagation of its germplasm. Therefore, the present study was designed to evaluate the reproductive as well as metabolic endocrinological profiles in 24:00 h in intact adult mithun bulls during different seasons (winter, spring, summer and autumn) to know the rhythmic changes and flow pattern of the endocrinological profiles to improve its reproductive efficiency. Experimental mithun bulls (n = 6; age: 5-6 years; body condition score: 5-6 out of 10, classified as good) were selected for the study. Endocrinological profiles, follicle stimulating hormone (FSH), luteinizing hormone/interstitial cell stimulating hormone (LH/ICSH), testosterone, cortisol, thyroxine (T4), insulin like growth factor-1 (IGF-1), prolactin and melatonin (MT) were estimated at 04:00 h interval for one whole day in four seasons. The analysis was completed in two different ways as different times of collection (08:00, 12:00, 16:00, 20:00, 24:00 and 04:00 h) and day (08:00 to 16:00 h) & night time (20:00 to 04:00 h) collections. Repeated measures ANOVA analysis revealed that the bulls in winter and spring had significantly (p < 0.05) higher FSH, LH, testosterone, T4, IGF-1 and MT than those in summer whereas the bulls in summer had significantly higher cortisol and prolactin than those in winter and spring seasons. Similarly FSH, LH, testosterone, T4, IGF-1 and MT were significantly (p < 0.05) higher in night than in day time collections whereas cortisol and prolactin were significantly (p < 0.05) higher in day than in night time collections in different seasons. Correlation analysis revealed that FSH, LH, testosterone, T4, IGF-1 and MT had significant (p < 0.05) positive correlation with each other whereas these had significant (p < 0.05) negative correlation with cortisol and prolactin. The study concludes that season and time of blood collection had significant effect on the endocrinological profiles in mithun bulls. Estimation of FSH, LH, testosterone, T4, IGF-1 and MT during night time and cortisol and prolactin during day time was more appropriate to get correct value of the endocrinological profiles. Spring and winter have significantly greater beneficial effects than summer on reproduction and artificial breeding programs in mithun species in the semi-intensive management in the present location.

Slow release exogenous melatonin modulates scrotal circumference and testicular parameters, libido, endocrinological profiles and antioxidant and oxidative stress profiles in mithun.

Mithun (Bos frontalis) is a unique domestic free-range bovine species available in North Eastern hilly (NEH) regions of India and is reared for its protein rich meat. Although, mithun suffers from severe non-cyclical population fluctuations, it is not yet declared as endangered. Therefore, present study was conducted to assess the effect of slow release subcutaneous exogenous melatonin (MT) implant on sexual behaviour, scrotal circumference (SC) and testicular parameters, endocrinological profiles and antioxidant and oxidative stress profiles in mithun during different seasons (winter, spring, summer and autumn) to improve its reproductive efficiency. Experimental mithun bulls (5-6 years of age) were selected and divided randomly into two groups, Gr I: Control (n = 6) and Gr II: Treatment (n = 6; melatonin implant @ 18mg/50 kg B. Wt). Scrotal circumference and testicular parameters [total testicular volume and weight], endocrinological profiles [follicle stimulating hormone (FSH), luteinizing hormone/interstitial cell stimulating hormone (LH/ICSH), testosterone, thyroxine (T4), cortisol, prolactin and melatonin (MT)], sex behaviour profiles [libido score, mating ability score and sexual behaviour score], antioxidant profiles [total antioxidant capacity (TAC), catalase (CAT), glutathione (GSH), glutathione reductase (GSHRx) and superoxide dismutase (SOD)] and oxidative stress profile [malondialdehyde (MDA)] were estimated. Statistical analysis revealed that these experimental profiles differed between treatment and control groups within the seasons and among the seasons within the experimental groups. FSH, LH, testosterone, T4 and MT were higher and cortisol and prolactin were lower in spring and winter than in summer season. Concentration of FSH, LH, testosterone and MT were higher and concentration of T4, cortisol and prolactin were lower in MT treated than in untreated control group. Similarly, sexual behavioural scores, SC, testicular parameters and antioxidant profiles were higher and oxidative stress profile was lower in MT treated than in untreated control group and in winter and spring than in summer season. The study concluded that exogenous slow-release melatonin implantation and spring and winter seasons had significant beneficial effects in improvement of the antioxidant profiles, minimization of oxidative stress with cascading beneficial effects on endocrinological profiles, SC, testicular parameters and libido, which will improve the semen production, higher sperm cryo-survivability and fertility rate in mithun species.

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.

Seroprevalence of Toxoplasma gondii in mithun (Bos frontalis) from north eastern hilly region of India.

Mithun (Bos frontalis) is mostly utilized for meat purpose by the local tribal people of north eastern hilly region of India. Meat born diseases are very important issues for the people of these areas from the public health point of view. In order to realize the issues, the serological prevalence of Toxoplasmosis was carried out as per ELISA kit (CHEKIT* TOXOTEST, IDEXX Laboratory, USA) to find out Toxoplasma gondii antibody. As a whole, out of 195 animals examined, only 8 (4.10 %) animals were found to be suspected and one (0.51 %) animal was  found to be positive in this precious animal of the north eastern region.