Seroprevalence of bluetongue and presence of viral antigen and type-specific neutralizing antibodies in goats in Tripura,a state at Indo-Bangladesh border of northeastern India

Tropical Animal Health and Production - Bluetongue (BT) is a notifiable multiple species transboundary viral disease of domestic and wild ruminants. Though the disease is enzootic in India, little...     

Molecular breeding for resistance to black rot [<Emphasis Type="Italic">Xanthomonas campestris</Emphasis> pv. <Emphasis Type="Italic">campestris</Emphasis> (Pammel) Dowson] in <Emphasis Type="Italic">Brassicas</Emphasis>: recent advances

The Brassicas are affected by several diseases, of which black rot, Xanthomonas campestris pv. campestris (Pam.) Dowson (Xcc), is one of the most widespread and devastating worldwide. The black rot bacteria causes systemic infection in the susceptible plants and penetrate the plants through the hydathodes or wounds. Typical disease symptoms are ‘V’ shaped necrotic lesions appearing from the leaf margins with blackened veins. Periodic outbreaks of the black rot pathogen have occurred worldwide, especially in the continental regions, where high temperatures and humidity favor the incidence of disease occurrence causing huge yield loss. The challenge to control the losses in vegetable brassicas production is made more difficult by the adverse climatic changes and evolution of new pathogenic races. The development of black rot resistant hybrids/varieties is the most reliable long term practical solution for effective disease control. Identification of new resistant genetic resources, tightly linked markers with resistance loci and QTL mapping would facilitate the breeding programme for black rot resistance. Information regarding genetics of resistance and mapping of resistance genes/QTLs will accelerate the marker assisted resistance breeding in brassica crops against Xcc. In future we need to identify the race specific candidate genes for and their validation through transgenics and gene expression. Moreover, it is imperative to identify functional markers for resistance genes through identification of R gene families and their relationship with resistance expression. This comprehensive review will help the researchers working in this area to understand the dynamics of black resistance breeding and to formulate future breeding strategies.     

RELEVANCE OF A RAPID APPRAISAL APPROACH TO IDENTIFY LOCALLY AVAILABLE FEED INGREDIENTS TO SMALL-SCALE NILE TILAPIA (Oreochromis niloticus L.) AQUACULTURE

Applications of a rapid appraisal approach to identify locally available feed ingredients in feed formulation, production, and socio-economics of Nile tilapia aquaculture in Bangladesh are discussed. Three diets of 35%, 30%, and 25% crude protein were formulated using locally available ingredients, and their essential amino acid profiles were assessed for Nile tilapia. Six production scenarios were constructed using these diets and two culture periods of 100 and 150 days were considered. The production scenarios with 35% protein yielded the highest productivity and profitability over the 150-day culture period followed by the 30% protein scenario. Identification of locally available ingredients and their application in small-scale Nile tilapia aquaculture may lead to: (1) increased availability of inexpensive sources of fish production for poor people; (2) increased fish consumption; (3) increased self employment and involvement of women in productive activities; and (4) increased household income to reduce poverty.     

Experiments on rearing exotic carp fingerlings in composite fish culture in India

The results of four field experiments on rearing fry to fingerlings of mainly exotic carp, Hypophthalmichthys molitrix, Ctenopharyngodon idella and Cyprinus carpio var. communis conducted for three- and six-month periods during 1971–1975 are presented. In one experiment Labeo rohita, an indigenous species was also introduced as a compatible species. Fry were stocked at densities of 200 000 and 250 000 per hectare in the three-month period and at 100 000 and 250 000 per hectare in the six-month period.Under pond fertilization and supplementary feeding a high percentage of fingerling survival was recorded; the aggregate percentages ranging between 71.50 and 91.16 in the three-month period and 61.26 and 89.03 in the six-month period.     

Rapid fabrication and optimization of silk fibers supported and stabilized MnO<Subscript>2</Subscript> catalysts

We report on the in situ synthesis and stabilization of manganese dioxide (MnO₂) onto four different silk yarns (mulberry, tasar, muga and eri silks). A new ultrasound-assisted procedure was used to reduce permanganate (MnO₄ ^?) and yielded MnO₂ nanoparticles (NPs) on/in the different silk fibers. Using a factorial design we assessed the influence of the silk type, manganese precursor concentration, sonication time, and temperature. The results indicated no measurable effect of the process parameters on the silk structures, but significant correlation with the rate of degradation of methylene blue (MB) and the fraction of permanganate consumed. Further optimization of the factorial model identified the optimal process conditions for each silks: mulberry (150 min sonication, 20 mM permanganate), eri (360 min, 10 mM), tasar (150 min, 10 mM) and Muga (20 min, 10 mM). The operational stability (successive catalysis) of the optimum hybrids showed good performance over 5 cycles and most importantly reduced direct dye absorption relatively to dye oxidation. Overall, we found that all silks could template the formation and stabilization of different MnO₂ polymorphs and yielded catalytic instead of stoichiometric hybrid fibers.     

Effect of elevated carbon dioxide on growth,nutrient partitioning,and uptake of major nutrients by soybean under varied nitrogen application levels

Rising carbon dioxide (CO₂) concentration causes fertilization effects resulting in enhanced crop biomass and yields and thus likely enhances nutrient demand of plants. Hence, this field study was carried out to investigate the effects of elevated CO₂ and N on biomass yield, nutrient partitioning, and uptake of major nutrients by soybean (Glycine max L.) using open‐top chambers (OTCs) of 4 m × 4 m size. Soybean was grown in OTCs under two CO₂ [ambient and elevated (535 ± 36.9 mg L^?1)] and four N levels during July to October 2016. The four N levels were N₀, N₅₀, N₁₀₀, and N₁₅₀ referring to 0, 50, 100, and 150% recommended dose of N. Both CO₂ and N significantly affected biomass and grain yield, though the interaction was non‐significant. CO₂ enrichment produced 30–65% higher biomass and 26–59% higher grain yield under various N levels. As compared to the optimum N application (N₁₀₀), the CO₂‐mediated increment in biomass yield decreased with either lower or higher N application, with the response being lowest at N₁₅₀. As compared to ambient concentration, elevated CO₂ resulted in significant reduction of seed P concentration at all N application levels but at N₁₅₀, an opposite trend was observed. The decrease in seed P was maximum at N₀ and N₅₀ (7–9%) and by 3% at N₁₀₀, whereas there was a gain of 7.5% at N₁₅₀. The seed N and K concentrations were not affected either by CO₂ or N application. Total N, P, and K uptake at harvest were significantly affected by CO₂ and N, but not by CO₂ × N interaction. Elevated CO₂ resulted higher uptake of N by 18–61%, P by 23–62%, and K by 22–62% under various N treatments.     

DEMAND FOR FISH IN THE PHILIPPINES: A DISAGGREGATED ANALYSIS

ABSTRACT

This paper sought to establish the fish consumption pattern of Filipino households and estimate the price and income elasticities of fish demand by species, as well as by income groups, i.e., low, middle, and high income. The study used the countrywide Family Income and Expenditure Survey (FIES) for year 2000 of the National Statistics Office, which includes over 39,000 households. A three-stage budgeting framework was used in the analysis, which estimated food and fish expenditure functions in the first and second stages, respectively. In the third stage, a system of demand equations for fish by species was estimated using a quadratic almost ideal demand system (QUAIDS) model. Parameter estimates of the model were corrected through the Heckman procedure to remove the possible bias brought about by zero consumption of certain fish species resulting from nonpreference or infrequent purchases. Results showed that estimated price and income elasticities of demand varied substantially across fish type and across income groups. All 11 fish types included in the study were found to have positive income elasticity for all income levels. Hence, fish in general can be considered normal goods, including processed fish. However, the high-priced fish types generated elasticity values greater than one, which rendered them as luxury food fish. Own-price elasticity, on the other hand, was found to be elastic in most species with values increasing as consumers climbed up the income ladder. This observation, however, was not true in the case of milkfish and tilapia (two most popular species in the country) where price responsiveness of demand was found to be higher among the lower-income groups.     

Mathematical Model of Channel Catfish Foodfish Production in Multiple-Batch

Market size requirements for catfish change periodically, and catfish farmers must adjust quickly. Data from catfish pond studies at the University of Arkansas at Pine Bluff (UAPB) were used to develop mathematical models of catfish foodfish in multiple-batch culture across a variety of management alternatives. Two different functional forms (Cobb–Douglas and a modified translog) were each developed into average and stochastic frontier models. Inefficiency terms were found to be non-significant in the frontier models, thus making the average and frontier models equivalent. In the average regression models, the modified translog form demonstrated superior statistical values as compared to the Cobb–Douglas form, but the latter resulted in lower prediction error and was validated with the Chow test when used to predict observations from commercial catfish farms. This approach appears to have merit from the perspective of its statistical properties, and represents a step towards development of a model that could be used for farm management purposes.