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.     

Pharmacokinetics of diclofenac and its interaction with enrofloxacin in sheep

The pharmacokinetics of diclofenac was investigated in sheep given diclofenac alone (1mgkg(-1), i.v. or i.m.) and in combination with enrofloxacin (5mgkg(-1), i.v.). The plasma concentration-time data following i.v. administration of diclofenac was best described by a two compartment open pharmacokinetic model. The elimination half-life (t(1/2beta)), area under concentration-time-curve (AUC), volume of distribution (Vd(area)), mean residence time (MRT) and total body clearance (Cl(B)) were 1.03+/-0.18h, 12.17+/-1.98microg h ml(-1), 0.14+/-0.02Lkg(-1), 1.36+/-0.16h and 0.10+/-0.02Lkg(-1)h(-1), respectively. Following i.m. administration of diclofenac alone and in conjunction with enrofloxacin, the plasma concentration-time data best fitted to a one compartment open model. The t(1/2beta), AUC, Vd(area), MRT and Cl(B) were 1.33+/-0.10h, 7.32+/-1.01microg h mL(-1), 0.13+/-0.01Lkg(-1) and 0.07+/-0.01Lkg(-1)h(-1), respectively. Co-administration of enrofloxacin did not affect Vd(area) and MRT but absorption rate constant (K(a)), beta, t1/2Ka, t1/2beta, AUC, AUMC, Cl(B) and bioavailability (F) were significantly increased. This may be due to direct inhibition of cytochrome P(450) isozymes by enrofloxacin. A dose of 1.4mgkg(-1) of diclofenac administered every 6h may be appropriate for use in sheep.     

Assessment of different methods of rice (Oryza sativa. L) cultivation affecting growth parameters, soil chemical, biological, and microbiological properties, water saving, and grain yield in rice–rice system

Field experiments were conducted at DRR farm located at ICRISAT, Patancheru, in sandy clay loam soils during four seasons, Kharif 2008, Rabi 2008–2009, Kharif 2009 and Rabi 2009–2010, to investigate growth parameters, water-saving potential, root characteristics, chemical, biological, and microbial properties of rhizosphere soil, and grain yield of rice (Oryza sativa L.) by comparing the plants grown with system of rice intensification (SRI) methods, with organic or organic + inorganic fertilization, against current recommended best management practices (BMP). All the growth parameters including plant height, effective tillers (10–45 %), panicle length, dry matter, root dry weight (24–57 %), and root volume (10–66 %) were found to be significantly higher with in SRI-organic + inorganic over BMP. With SRI-organic fertilization, growth parameters showed inconsistent results; however, root dry weight (3–77 %) and root volume (31–162 %) were found significantly superior compared to BMP. Grain yield was found significantly higher in SRI-organic + inorganic (12–23 and 4–35 % in the Kharif and Rabi seasons, respectively), while with SRI-organic management, yield was found higher (4–34 %) only in the Rabi seasons compared to BMP. An average of 31 and 37 % of irrigation water were saved during Kharif and Rabi seasons, respectively, with both SRI methods of rice cultivation compared to BMP. Further, total nitrogen, organic carbon%, soil dehydrogenase, microbial biomass carbon, total bacteria, fungi, and actinomycetes were found higher in the two SRI plots in comparison to BMP. It is concluded that SRI practices create favorable conditions for beneficial soil microbes to prosper, save irrigation water, and increase grain yield.     

Near-Infrared-Spectroscopy for Determination of Carbon and Nitrogen in Indian Soils

The present study aims to evaluate the potential of near-infrared reflectance (NIR) spectroscopy to determine the carbon and nitrogen content in soils and also to assess the effectiveness of NIR spectroscopy to predict carbon and nitrogen content in freshly collected soil samples. Soil samples (n = 179) were collected from different locations in India. Soil carbon and nitrogen contents were successfully predicted (R² = 0.90 for carbon and R² = 0.85 for nitrogen) by NIR spectroscopy. The root mean square error (RMSE) and ratio performance deviation (RPD) for the validation of predicted equations for carbon and nitrogen were 0.83 and 2.83 and 0.01 and 6.98, respectively. The efficacy of NIR spectroscopy on the prediction of carbon and nitrogen content in Indian soils is highly reliable. Water content in soil samples could affect the NIR absorbance spectra and in turn affect the quantification of carbon and nitrogen.     

Environmental Assessment of Channel Catfish Ictalurus punctatus Farming in Alabama

An environmental assessment was made of Alabama channel catfish Ictalurus punctatus farming which is concentrated in the west‐central region of the state. There are about 10,000 ha of production ponds with 10.7% of the area for fry and fingerlings and 89.3% for food fish. Food fish production was about 40,800 tons in 1997. Watershed ponds filled by rainfall and runoff make up 76% of total pond area. Water levels in many of these ponds are maintained in dry weather with well water. The other ponds are embankment ponds supplied by well water. Harvest is primarily by seine‐through procedures and ponds are not drained frequently. The main points related to Alabama catfish farming and environment issues are as follows: 1) catfish farming in Alabama is conservative of water, and excluding storm overflow, about two pond volumes are intentionally discharged from each pond in 15 yr; 2) overflow from ponds following rains occurs mostly in winter and early spring when pond water quality is good and stream discharge volume is high; 3) total suspended solids concentrations in pond effluents were high, and the main sources of total suspended solids were erosion of embankments, pond bottoms, and discharge ditches; 4) concentrations of nitrogen and phosphorus in effluents were not high, but annual effluent loads of these two nutrients were greater than for typical row crops in Alabama; 5) ground water use by the industry is about 86,000 m³/d, but seepage from ponds returns water to aquifers; 6) there is little use of medicated feeds; 7) copper sulfate is used to control blue‐green algae and off‐flavor in ponds, but copper is rapidly lost from pond water; 8) although sodium chloride is applied to ponds to control nitrite toxicity, stream or ground water salinization has not resulted from this practice; 9) fertilizers are applied two or three times annually to fry and fingerling ponds and occasionally to grow‐out ponds; 10) hydrated lime is applied occasionally at 50 to 100 kg/ha but this does not cause high pH in pond waters or effluents; 11) accumulated sediment removed from pond bottoms is used to repair embankments and not discarded outside ponds; 12) sampling above and below catfish pond outfalls on eight streams revealed few differences in stream water quality; 13) electricity used for pumping water and mechanical aeration is only 0.90 kW h/kg of production; 14) each metric ton of fish meal used in feeds yields about 10 tons of dressed catfish. Reduction in effluent volume through water reuse and effluent treatment in settling basins or wetlands does not appear feasible on most farms. However, some management practices are recommended for reducing the volume and improving the quality of channel catfish pond effluents.     

Modulation of key metabolic enzyme of <Emphasis Type="Italic">Labeo rohita</Emphasis> (Hamilton) juvenile: effect of dietary starch type,protein level and exogenous α-amylase in the diet

A 60-day feeding trial was conducted to delineate the effect of both gelatinized (G) and non-gelatinized (NG) corn with or without supplementation of exogenous α-amylase, either at optimum (35%) or sub-optimum (27%) protein levels, on blood glucose, and the key metabolic enzymes of glycolysis (hexokinase, HK), gluconeogenesis (glucose-6 phosphatase, G6Pase and fructose-1,6 bisphosphatase, FBPase), lipogenesis (glucose-6 phaosphate dehydrogenase, G6PD) and amino acid metabolism (alanine amino transfersae, ALT and aspartate amino transferase, AST) in Labeo rohita. Three hundred and sixty juveniles (average weight 10 ± 0.15 g) were randomly distributed into 12 treatment groups with each of two replicates. Twelve semi-purified diets containing either 35 or 27% crude protein were prepared by including G or NG corn as carbohydrate source with different levels of microbial α-amylase (0, 50, 100 and 150 mg kg⁻¹). The G corn fed groups showed significantly higher (P < 0.05) blood glucose and G6PD activity, whereas G6Pase, FBPase, ALT and AST activity in liver was higher in the NG corn fed group. Dietary corn type, α-amylase level in diet or their interaction had no significant effect (P > 0.05) on liver HK activity, but the optimum crude protein (35%) fed group showed higher HK activity than their low protein counterparts. The sub-optimum crude protein (27%) fed group showed significantly higher (P < 0.05) G6PD activity than the optimum protein fed group, whereas the reverse trend was observed for HK, G6Pase, FBPase, ALT and AST activity. Addition of 50 mg α-amylase kg⁻¹ feed showed increased blood glucose and G6PD activity of the NG corn fed group, whereas the reverse trend was found for G6Pase, FBPase, ALT and AST activity in liver, which was similar to that of the G or NG corn supplemented with 100/150 mg α-amylase kg⁻¹ feed. Data on enzyme activities suggest that NG corn in the diet significantly induced more gluconeogenic and amino acid metabolic enzyme activity, whereas G corn induced increased lipogenic enzyme activity. Increased amino acid catabolic enzyme (ALT and AST) activity was observed either at optimum protein (35%) irrespective of corn type or NG corn without supplementation of α-amylase irrespective of protein level in the diet.     

Identification and pathogenicity of Alternaria alternata causing leaf spot and blight disease of Ailanthus excelsa in India

Alternaria leaf spot of Ailanthus excelsa is generally considered as minor disease in India. Recently, severe disease outbreaks were recorded in the nursery of the Forest Research Institute, Dehradun, progeny trial at Jhumpa, Haryana, and in a nearby farm field. Leaf symptoms included small circular, brown, necrotic spots with a chlorotic halo. With severe infections, leaf spots coalesced and resulted in leaf blight. A small‐spored Alternaria with concatenated conidia was isolated consistently from the leaf samples with spot symptoms. Sequence analyses of the internal transcribed spacer (ITS) region of ribosomal DNA (rDNA) and the translation elongation factor 1‐alpha (tef‐1α) gene region of two fungal isolates confirmed the species as A. alternata. In detached leaf assays, both isolates produced symptoms similar to those observed on the nursery/field‐grown plants. To validate the detached leaf assay result, pathogenicity was also demonstrated on whole plants in a glasshouse. Koch's postulates were fulfilled by re‐isolating A. alternata from the inoculated leaves. This work is the first to confirm that A. alternata is associated with leaf spot and blight disease of A. excelsa in India.