Dietary zinc potentiates thermal tolerance and cellular stress protection of Pangasius hypophthalmus reared under lead and thermal stress

Zinc micronutrient is the second most abundant trace element in the animal body, as it could not be stored in the body; hence, regular dietary zinc is required for animals. With this backdrops a 60 days feeding trial was conducted to study the effect of dietary zinc on the thermal tolerance and cellular metabolic stress of Pangasius hypophthalmus reared under Pb (1/21th of LC₅₀, 4 ppm) and elevated temperature (34°C). Three isocaloric and isonitrogenous diets with Zn‐0, 10 and 20 mg/kg were prepared. Two hundred seventy‐three fish were randomly distributed into seven treatments in triplicate in completely randomized forms. Dietary zinc supplementation had remarkable (p < .01) changes on thermal tolerance of P. hypophthalmus viz. CTmin (critical temperature minima) and LTmin (lethal temperature minima), CTmax (critical temperature maxima) and LTmax (lethal temperature maxima). The positive correlations were also observed between CTmin and LTmin (Y = ?0.707 + 6.59x, R², 0.875) and CTmax and LTmax (Y = ?0.923 + 2.45x, R², 0.960). The oxidative stress (catalase, superoxide dismutase and glutathione‐s‐transferase) and lipid peroxidation were significantly reduced and neurotransmitter enzyme (AChE) was significantly enhanced with zinc supplementation at the end of the thermal tolerance. The present study concluded that thermal tolerance of P. hypophthalmus enhanced by zinc supplementation through CTmax LTmax and CTmin LTmin and also by strengthening the antioxidative status along with neurotransmitter enzymes.     

Biochemical Alterations in the Blood Plasma of Rats Associated with Hepatotoxicity Induced by Eupatorium adenophorum

Eupatorium adenophorum (Crofton weed), a native of Central America, has appeared as a major weed in several areas in different parts of the world. Horses that eat this plant are poisoned on prolonged exposure. Toxicity due to consumption of this plant by other grazing animals is not clear. Administration of freeze-dried leaf powder to mice results in hepatotoxicity. Earlier attempts to produce toxicity in rats using the leaves of this plant were not successful. In the present study, administration of oven-dried E. adenophorum leaves collected at the flowering stage elicited hepatotoxicity in rats. The affected animals had a marked increase in the concentration of plasma bilirubin and in the activities of 5-nucleotidase, alkaline phosphatase, aspartate aminotransferase, alanine aminotransferase and lactate dehydrogenase. There were no significant differences in plasma creatinine, urea or total protein values in the affected animals compared to controls. The livers of the affected animals had focal areas of necrosis throughout the parenchyma and hepatocytes showed megalocytosis. The bile ducts were dilated and the epithelium showed degenerative to necrotic changes. The alterations in bilirubin, enzymes and histopathological changes imply cholestasis and liver injury.     

Classical swine fever in India: current status and future perspective

Classical swine fever (CSF) is a globally significant disease of swine caused by classical swine fever virus. The virus affects the wild boars and pigs of all age groups, leading to acute, chronic, late-onset or in-apparent course of the disease. The disease causes great economic loss to the piggery industry due to mortality, stunted growth, poor reproductive performance, and by impeding the international trade of pig and pig products. In India, CSF outbreaks are reported from most of the states wherever pig rearing is practiced and more frequently from northeast states. In spite of the highly devastating nature and frequent outbreaks, CSF remained underestimated and neglected for decades in India. The country requires rapid and sensitive diagnostic tests for an early detection of infection to limit the spread of the disease. Also, effective prophylactics are required to help in control and eradication of the disease for the development of the piggery industry. This review looks into the economic impact; epidemiology of CSF highlighting the temporal and spatial occurrence of outbreaks in the last two decades, circulation, and emergence of the virus genotypes in and around the country; and the constraints in the disease control, with the aim to update the knowledge of current status of the disease in India. The article also emphasizes the importance of the disease and the need to develop rapid specific diagnostics and effective measures to eradicate the disease.     

Nonspecific immunostimulation against viruses

A trypsinized preparation from chromogenic selected strain of Mycobacterium phlei (NSI) stimulated the recipient immune system non-specifically against a variety of viruses viz. Rabies virus (RNA virus). Marek's disease (DNA virus) and Foot and Mouth disease virus (RNA virus) in phylogenetically different hosts like mice, chicks and guinea pigs respectively. Investigation into mechanisms of such nonspecific immunostimulation revealed that there was induction of strong cell mediated immune response (CMIR) against both specific as well as to nonspecific viral antigens as evinced by LMIT, lymphokine (LyIF) assay and lymphocyte transformation test etc. There was induction of appreciable quantity of "Infectivity inhibiting substance(s)" (IIS) which was not the classical antibody (Ig) in the serum of NSI inoculated animals and birds. This substance(s) neutralized FMD, IBR, rabies and Newcastle disease virus in cell culture, mice and in embryonated eggs. Electrophoretic separation of the NSI induced serum revealed an increase in beta fraction of globulin.     

Enhanced mucosal immune response in cattle persistently infected with foot-and-mouth disease virus

The mucosal immune response to foot-and-mouth disease virus (FMDV) type Asia 1 was examined in experimentally infected cattle by assaying antibodies by the virus-neutralizing test (VNT) and IgA ELISA in two secretory fluids, oesophageal pharyngeal fluid (OPF) and oro-nasal fluid (ONF). Out of 17 animals infected by the intradermo-lingual route, 12 became persistently infected (carriers), as defined by positive antigen capture RT-PCR reactions for FMDV RNA in OPF samples collected at 28 days or later after exposure. This proportion of carriers (71%) with FMDV Asia 1 is comparable to other serotypes of the virus. When the two groups were examined, the carriers and non-carriers showed no difference in the serum antibody titre until the end of the experiment at 182 days post-infection (DPI). However, despite an initial similarity significantly higher neutralizing antibody titres and FMDV-specific IgA response were detected among the carriers than the non-carriers in both of the secretory fluids. The response was higher and more stable in ONF compared to OPF. Thus, mucosal antibody assays have the potential to be used as a means of differentiating carrier from non-carrier cattle. Furthermore, the findings are consistent with the higher mucosal antibody response in carriers being an effect of persistent infection rather than the cause.     

Mapping and validation of QTLs for resistance to an Indian isolate of Ascochyta blight pathogen in chickpea

Ascochyta blight (AB) caused by Ascochyta rabiei, is globally the most important foliar disease that limits the productivity of chickpea (Cicer arietinum L.). An intraspecific linkage map of cultivated chickpea was constructed using an F₂ population derived from a cross between an AB susceptible parent ICC 4991 (Pb 7) and an AB resistant parent ICCV 04516. The resultant map consisted of 82 simple sequence repeat (SSR) markers and 2 expressed sequence tag (EST) markers covering 10 linkage groups, spanning a distance of 724.4 cM with an average marker density of 1 marker per 8.6 cM. Three quantitative trait loci (QTLs) were identified that contributed to resistance to an Indian isolate of AB, based on the seedling and adult plant reaction. QTL1 was mapped to LG3 linked to marker TR58 and explained 18.6% of the phenotypic variance (R ²) for AB resistance at the adult plant stage. QTL2 and QTL3 were both mapped to LG4 close to four SSR markers and accounted for 7.7% and 9.3%, respectively, of the total phenotypic variance for AB resistance at seedling stage. The SSR markers which flanked the AB QTLs were validated in a half-sib population derived from the same resistant parent ICCV 04516. Markers TA146 and TR20, linked to QTL2 were shown to be significantly associated with AB resistance at the seedling stage in this half-sib population. The markers linked to these QTLs can be utilized in marker-assisted breeding for AB resistance in chickpea.     

Validation and Marker-Assisted Selection of Stem Rust Resistance Gene Sr2 in Indian Wheat Using Gel-Based and Gel-Free Methods

Journal of Crop Science and Biotechnology - Stem rust resistance gene Sr2 is an important slow-rusting gene which has provided resistance against stem rust for many years. The Sr2 gene has durable...