Appraisal of growth curve in Sirohi goat using non-linear growth curve models.

In the present study, the appropriateness of five non-linear mixed growth curve models was studied to describe body weight growth of Sirohi male and female goat from birth to 12 months of age. Using selected functions, biologically pertinent variables were estimated for each goat from the Brody, Gompertz, Logistic, Richard, and Weibull. In addition, the males had higher asymptotic live weight 'A' than female counterparts. The highest values for 'B' parameter were observed for Weibull in both sexes, whereas the lowest value was calculated from Gompertz model. Maturity rate 'K' was higher in males than that of females. Male goat had heavier inflection weight 'm' and higher age than females for all the models. The best model was determined by considering the following goodness of fit criteria: coefficient of determination (R2), mean square error (RMSE), mean absolute error (MAE), and mean square absolute percentage error (MAPE). In both the sexes, all the non-linear regression models fitted the data well with high coefficient of determination (R2) ranging from 0.99 to 0.89 and 0.99 to 0.91 for male and female respectively. The Brody model provided the best fit of growth curve in both males and females and the lowest fit of growth were provided by Weibull model. We therefore, concluded that the Brody model was favorable for determining body weight in both sexes of Sirohi goat.

Assessment of adaptability of zebu cattle (Bos indicus) breeds in two different climatic conditions: using cytogenetic techniques on genome integrity.

The aim of this study was to evaluate the genome integrity so as to assess the adaptability of three breeds of indigenous cattle reared under arid and semi-arid regions of Rajasthan (Bikaner) and Haryana (Karnal) India. The cattle were of homogenous group (same age and sex) of indigenous breeds viz. Sahiwal, Tharparkar and Kankrej. A total of 100 animals were selected for this study from both climatic conditions. The sister chromatid exchanges (SCE's), chromosomal gaps and chromatid breaks were observed in metaphase plates of chromosome preparations obtained from in vitro culture of peripheral blood lymphocytes. The mean number of breaks and gaps in Sahiwal and Tharparkar of semi-arid zone were 8.56 ± 3.16, 6.4 ± 3.39 and 8.72 ± 2.04, 3.52 ± 6.29, respectively. Similarly, the mean number of breaks and gaps in Tharparkar and Kankrej cattle of arid zone were 5.26 ± 1.76, 2.74 ± 1.76 and 5.24 ± 1.84, 2.5 ± 1.26, respectively. The frequency of SCEs in chromosomes was found significantly higher (P < 0.05) in Tharparkar of semi-arid region (4.72 ± 1.55) compared to arid region (2.83 ± 1.01). Similarly, the frequency of SCEs was found to be 4.0 ± 1.41 in the Sahiwal of semi-arid region and 2.69 ± 1.12 in Kankrej of arid zone. Statistical analysis revealed significant differences (P < 0.05) amongst the different zones, i.e. arid and semi-arid, whereas no significant difference (P > 0.05) was observed in the same zone. The analysis of frequency of CAs and SCEs revealed significant effects of environmental conditions on the genome integrity of animals, thereby indicating an association with their adaptability.

Heat stress and antioxidant enzyme activity in bubaline (Bubalus bubalis) oocytes during in vitro maturation.

In vitro environments like heat stress usually increase the production of reactive oxygen species in bubaline oocytes which have been implicated as one of the major causes for reduced developmental competence. Oocytes during meiotic maturation are sensitive to oxidative stress, and heat stress accelerates cellular metabolism, resulting in the higher production of free radicals. Therefore, the aim of present work was to assess the impact of heat stress during meiotic maturation on bubaline cumulus-oocyte complexes (COC), denuded oocytes (DO), and cumulus cell mass in terms of their oxidative status. Accordingly, for control group, COC were matured at 38.5 °C for complete 24 h of meiotic maturation and heat stress of 40.5 and 41.5 °C was applied to COC during the first 12 h of maturation and then moved to 38.5 °C for rest of the 12 h. In another group, COC after maturation were denuded from the surrounding cumulus cells by manual pipetting. Results indicated that the production of reactive oxygen species (ROS), lipid peroxides, and nitric oxide (NO) was significantly (P < 0.05) higher in the oocytes subjected to heat stress (40.5 and 41.5 °C) during meiotic maturation compared to the oocytes matured under standard in vitro culture conditions (38.5 °C). Also, the antioxidant enzymatic activities of superoxide dismutase, catalase, glutathione peroxidase, and glutathione reductase were significantly (P < 0.05) increased in all the treatment groups compared to the control group. Therefore, the present study clearly establishes that heat stress ensues oxidative stress in bubaline oocytes which triggers the induction of antioxidant enzymatic defense system for scavenging the ROS.

A study on steroidogenic elaborations of stroma and their regulation in response to ovarian hormones in goats.

Stromal tissue is an essential componenlt of the ovary not only for providing structural support but also for contributing to the early follicular growth with their bi-directional paracrine signaling. Estradiol is a major female hormone mainly secreted by the follicular cells in the ovary. To examine the relationship between 17ß-estradiol and the factors involved in androgen production in stromal cells, ovarian stromal cells were cultured in the graded concentrations (50 and 100 ng/mL) of 17ß-estradiol for varying time periods (24 and 48 h). The cells were processed for transmission electron microscopy to study the changes in steroidogenic functions of the cells. The effect of estradiol treatment was also evaluated on the quantity of androgen production and abundance of steroidogenic enzymes and proteins. The results indicated 17ß-estradiol increased androgen production in ovarian stromal cells. In addition to enhanced androstenedione and testosterone production, estradiol stimulation was also based on the marked increase in abundance of mRNA transcript of steroidogenic enzymes [Star (Steroidogenic Acute Regulatory Protein), Cyp11a1, Cyp17a1, and hsd3b1 (3ß-hydroxysteroid dehydrogenase)], as well as abundances of StAR and CYP11A1 protein. Thus, 17ß-estradiol enhanced steroidogenesis in ovarian stromal cells. This study provided a basis for further exploration of regulation of steroidogenesis in ovarian stromal cells and the feedback mechanisms in association with estradiol.