Search

The age at first calving (AFC) has a huge impact on profitability in the dairy industry. It can be used as an indicator of fertility and productivity and it is also considered as an essential factor to ascertain the overall production performance of the animal. There are large variations in AFC in herd to herd, breed to breed and also country to country. This may be due to various factors that affect directly or indirectly on AFC; out of many factors, nutrition, body weight, environments, managements and genetics factors play a major role into attainment of puberty, sexual maturity and AFC. The current review covers various aspects of the seasonal influence of AFC on certain genetic variations and subsequent effect of these genetic variations in reproductive performances of the Murrah buffaloes. [ABSTRACT FROM AUTHOR]

Aim: An experiment was designed to evaluate the role of Vitamin E and glutathione in improving the seminal parameters during hypothermic storage of liquid semen at 4°C for 72 h. Materials and Methods: Thirty-six semen ejaculates were collected by artificial vagina from 6 bucks (Beetal) during the normal reproduction season (September to November) at weekly interval. The samples were centrifuged, and the seminal plasma was removed. The sperm pellet was diluted with Tris-based extender and divided into three groups. Group T1: Control samples without antioxidants, Group T2: Samples supplemented with tocopherol at 3 mM, and Group T3: Samples supplemented with glutathione at 1 mM. The samples were evaluated for progressive motility, percent liveability, percent abnormal spermatozoa, and acrosome integrity after liquid preservation for 0, 24, 48, and 72 h. The level of lipid peroxidation and antioxidant enzymes, namely, glutathione peroxidase (GPx) and superoxide dismutase (SOD) were estimated after liquid preservation for 0 and 72 h. Results: It was observed that, after storage of semen at 4°C up to 72 h, the progressive sperm motility, percent liveability, percent abnormal spermatozoa, and percent intact acrosomes were significantly (p<0.05) higher in group T2 and T3 samples as compared to control. However, the level of lipid peroxidation in T2 and T3 groups was significantly (p<0.05) lower after 72 h of incubation at 4°C. Similarly, GPx and SOD values were significantly (p<0.05) increased in T2 and T3 groups after 72 h of storage at 4°C. Conclusion: Thus, it can be concluded that Vitamin E and glutathione supplementation at 3 mM and 1 mM, respectively, while preserving the semen samples at 4°C helped in maintaining the seminal parameters up to 72 h and protected the spermatozoa from oxidative damage. [ABSTRACT FROM AUTHOR]

Sperm mitochondrion is one of the major susceptible organelles that get damaged during cryopreservation. The study aimed to minimize mitochondrial dysfunction and oxidative stress during sperm cryopreservation using mitochondria‐specific antioxidants. For this, semen was collected from five buffalo bulls (3 ejaculates/bull). The ejaculates were diluted in an low‐density lipoprotein‐based extender and divided into four equal aliquots. Mitochondria‐targeted antioxidant (MitoQ) was added at a final concentration of 0 (control), 0.02, 0.2 and 2 μM separately in each aliquotes and cryopreserved. The addition of MitoQ at a concentration of 0.02 μM improved post‐thaw sperm motility, plasma membrane integrity and able to sustain sperm motility for a longer time. To investigate MitoQ's effects on mitochondrial function, we measured mitochondrial membrane potential (MMP) using JC‐1 dye, superoxide production using Mitosox assay, and lipid peroxidation by TBARS assay. The supplementation of 0.02 μM MitoQ in the extender prevented the significant reduction of MMP and reduced superoxide production resulting in lower lipid peroxidation of sperm plasma membrane after cryopreservation. Further, we found that a higher concentration of MitoQ decreases MMP and increases mitochondrial superoxide production. In conclusion, MitoQ @ 0.02 μM can alleviate oxidative stress by regulating mitochondrial functionality in spermatozoa during cryopreservation. [ABSTRACT FROM AUTHOR]

Summary: The present study aimed to compensate dilution effect using additional seminal plasma (SP) in conventional (80 million (M) spermatozoa/ml) dose and low spermatozoa/dose (8M spermatozoa/ml). We also attempted to confirm whether removal of SP before the extension of ejaculates affects post‐thaw sperm quality of buffalo semen. For this, semen ejaculates (N = 15) were divided into four groups: control (CON), removal of SP by centrifugation (NSP), resuspension of the centrifuged semen pellet into SP (CEN) and extra supplementation of SP (ESP). All groups were diluted into two different semen doses to 20 and 2M spermatozoa/0.25 ml using tris egg yolk extender and subsequently cryopreserved. We found that neither addition nor removal of SP affected sperm motility, kinematics, longevity, mitochondrial superoxide production and high mitochondrial membrane potential (MMP). Further, the addition or removal of SP was not able to compensate dilution effect in 2M groups resulting in a significantly (p <.05) reduction in sperm motility, kinematics, sperm longevity, membrane integrity, MMP, and an increase production of mitochondrial superoxide. In conclusion, it appears that role of SP in the sperm cryopreservation process is insignificant. [ABSTRACT FROM AUTHOR]

The objective of the present study was to determine the effect of vitamin E supplementation in Tris-citric acid yolk glycerol extender on seminal and biochemical parameters of semen at the end of equilibration time (pre freezing stage) and after 24 hours freezing and thawing (post freezing stage) of semen. Significant improvement in progressive sperm motility, live spermatozoa, acrosomal integrity and MDA was observed in semen supplemented with vitamin E during pre freezing and post freezing stages. However, the release of glutamic oxaloacetic transaminase (GOT) did not differ significantly in both the groups. Thus inclusion of vitamin E in the extender prior to extension and freezing has shown improvement in post thaw quality of buffalo bull semen. [ABSTRACT FROM AUTHOR]

Reproductive managements of buffalo during the summer season a challenging task livestock's owner. There are different factors contributes to this condition; the most important are consequence of increased temperature and humidity that result in a decreased expression of overt sings of estrus and reduction in appetite and dry matter intake. The failure to express the overt signs of estrus is due to aberration in endocrine profile. Heat stress during the summer causes hyper-prolactinaemia, suppressing the secretion of gonadotropins, which alters the ovarian steroidogenesis. It also affects folliculogenesis, follicular fluid microenvironment and oocyte quality. A large number of hormonal regimens have been used with varying degree of efficacy in terms of estrus induction and conception rate. A combined strategy of improvement in environment, nutrition and management is pre-requisite for hormonal manipulation in order to improve productivity of buffaloes during the summer season. [ABSTRACT FROM AUTHOR]

Equine influenza viruses (EIVs) are responsible for acute contagious respiratory infection in equines and the disease remains a major threat for equine population throughout the world despite vaccination strategies in place. The present study was aimed to assess the suitability of BALB/c mice as a potential small animal model for preliminary screening of EI vaccine candidates. For this, we evaluated the immunogenicity and protective efficacy of an inactivated EIV (H3N8) vaccine in BALB/c mouse model after challenge with homologous H3N8 virus (Clade 2 virus, Florida sublineage) through serology, clinical signs, gross and histopathology lesions with grading, immunohistochemistry and virus quantification. Serological responses in immunized mice were evaluated by haemagglutination inhibition assay (HAI) and antibodies were subtyped by ELISA. The vaccine induced optimum protective antibody titre on 49 dpi along with balanced Th1/Th2 responses. Immunized mice were well protected against EIV challenge as evident by significant rise in serum antibody titre which concurred with mild clinical signs, early recovery, lower gross and histopathological lesions score, less severe intensity of viral antigen distribution, restricted virus replication in respiratory tract and less virus detection in nasal washes for short duration. The duration of the viral load was also lower and only for brief period as compared to unvaccinated challenged mice. In conclusion, induction of H3N8 specific antibody response and protection against H3N8 challenge proves that egg grown inactivated H3N8 whole virus vaccine would provide an effective intercession against H3N8 virus. In addition, BALB/c mouse can serve as an attractive tool for adjudging protective efficacy of vaccine candidates prior to final testing in equines. [ABSTRACT FROM AUTHOR]

Equine influenza viruses (EIV)—H3N8 continue to circulate in equine population throughout the world. They evolve by the process of antigenic drift that leads to substantial change in the antigenicity of the virus, thereby necessitating substitution of virus strain in the vaccines. This requires frequent testing of the new vaccines in the in vivo system; however, lack of an appropriate laboratory animal challenge model for testing protective efficacy of equine influenza vaccine candidates hinders the screening of new vaccines and other therapeutic approaches. In the present investigation, BALB/c mouse were explored for suitability for conducting pathogenecity studies for EIV. The BALB/c mice were inoculated intranasally @ 2×106.24 EID50 with EIV (H3N8) belonging to Clade 2 of Florida sublineage and monitored for setting up of infection and associated parameters. All mice inoculated with EIV exhibited clinical signs viz. loss in body weights, lethargy, dyspnea, etc, between 3 and 5 days which commensurate with lesions observed in the respiratory tract including rhinitis, tracheitis, bronchitis, bronchiolitis, alveolitis and diffuse interstitial pneumonia. Transmission electron microscopy, immunohistochemistry, virus quantification through titration and qRT-PCR demonstrated active viral infection in the upper and lower respiratory tract. Serology revealed rise in serum lactate dehydrogenase levels along with sero-conversion. The pattern of disease progression, pathological lesions and virus recovery from nasal washings and lungs in the present investigations in mice were comparable to natural and experimental EIV infection in equines. The findings establish BALB/c mice as small animal model for studying EIV (H3N8) infection and will have immense potential for dissecting viral pathogenesis, vaccine efficacy studies, preliminary screening of vaccine candidates and antiviral therapeutics against EIV. [ABSTRACT FROM AUTHOR]