Heat stress and effect of shade materials on hormonal and behavior response of dairy cattle: a review

In tropical countries, at high temperatures, several physiological rearrangements occur in cows as they attempt to facilitate heat dissipation and/or reduce metabolic heat production. Following exposure to heat, cattle appear to acclimatize within 2–7 weeks. The failure of homeostasis at high temperatures may lead to reduced productivity or even death. The situation is even worse when humidity adds to high temperature. Livestock with elevated body temperature exhibit lower DMI and growth with less efficiency, reducing profitability for dairy farms in hot and humid climates. Shading of feed and water also offers production advantages. Although several elaborate methods for reducing heat stress in cows have been reported, simple shade materials appear to be the most cost-effective methods that are currently applicable to tropical developing countries. Different materials are being used to provide shade during warm weather. The shade material determines the microclimate—it should be light, strong, durable, weatherproof, good looking and a bad conductor of heat, and free from tendency to condense moisture inside. This review discusses various shade materials and their advantages and disadvantages in different situations.     

Some characteristics of vaginal prolapse in Nepali buffaloes

Prolapse of vagina is one of the important maternal abnormalities during pregnancy in cattle and buffaloes. A field investigation was carried out on 26 Murrah graded buffaloes to study clinical characteristics of vaginal prolapse in buffaloes in Nepal. Fifty-seven percent of the 26 buffaloes with vaginal prolapse were either heifers or in first lactation. Sixty-five percent of the cases were in seventh month of pregnancy or later. About three quarters of the cases occurred between June and October. Twelve cases (63%) of the 19 animals excluding 7 heifers had a history of vaginal prolapse in previous gestations. A half of the buffaloes were showing prolapse of the vagina even when they were in standing position and showing moderate or vigorous straining. After the conventional treatments, twenty-three buffaloes retained the replaced vagina and calved normally. One animal aborted although the vagina was retained. Two buffaloes had severest degree of vaginal prolapse complicated with edema, injury and cyanosis, and they did not respond to the treatment. The two buffaloes had frequently recurrent prolapse and subsequently died. Early detection and prompt treatment may be imperative to control the vaginal prolapse in buffaloes.     

Role of micronutrients on quantitative traits and prospects of its accumulation in linseed (Linum usitatissimum L.)

The adequate growth of plants can be achieved only by a balanced ratio of biologically active nutrients in soil along with its readily availability. Linseed seems to be an advantageous secondary oilseed crop widely used in industrial purposes, which can serve additional purpose of phytoextraction of heavily infested soils with heavy metals. In this study, we have made an effort to find out the optimum dose of heavy metals necessary as micronutrients like copper (Cu), iron (Fe) and zinc (Zn) for the enhancement of linseed yield along with the distribution of heavy metals in different plant parts. Quantitative enhancement in different traits of linseed plant due to Cu, Fe and Zn fertilization especially for capsules per plant after maturity suggested positive association between heavy metal supply and morphological traits, which indirectly enhanced seed yield. There was a positive correlation between Zn supply and seed yield. In the treatments with Cu and Fe fertilization, seed yield was positively correlated to plant height, capsules per plant and seeds per five capsules. According to this study, it is concluded that linseed has the ability to accumulate majorly Fe followed by Cu and Zn.     

Regulation of the Amount of Starch in Plant Tissues by ADP Glucose Pyrophosphorylase

Starch, a major storage metabolite in plants, positively affects the agricultural yield of a number of crops. Its biosynthetic reactions use adenosine diphosphate glucose (ADPGlc) as a substrate; ADPGlc pyrophosphorylase, the enzyme involved in ADPGlc formation, is regulated by allosteric effectors. Evidence that this plastidial enzyme catalyzes a rate-limiting reaction in starch biosynthesis was derived by expression in plants of a gene that encodes a regulatory variant of this enzyme. Allosteric regulation was demonstrated to be the major physiological mechanism that controls starch biosynthesis. Thus, plant and bacterial systems for starch and glycogen biosynthesis are similar and distinct from yeast and mammalian systems, wherein glycogen synthase has been demonstrated to be the rate-limiting regulatory step.     

Biological Control of Late Leaf Spot of Peanut (Arachis hypogaea) with Chitinolytic Bacteria

ABSTRACT Late leaf spot (LLS), caused by Phaeoisariopsis personata, is a foliar disease of groundnut or peanut (Arachis hypogaea) with high economic and global importance. Antifungal and chitinolytic Bacillus circulans GRS 243 and Serratia marcescens GPS 5, selected among a collection of 393 peanut-associated bacteria, were applied as a prophylactic foliar spray and tested for control of LLS. Chitin-supplemented application of B. circulans GRS 243 and S. marcescens GPS 5 resulted in improved biological control of LLS disease. Supplementation of bacterial cells with 1% (wt/vol) colloidal chitin reduced lesion frequency by 60% compared with application of bacterial cells alone, in the greenhouse. Chitinsupplemented application of GRS 243 and GPS 5 also resulted in improved and stable control of LLS in a repeated field experiment and increased the pod yields by 62 and 75%, respectively, compared with the control. Chitin-supplemented application of GPS 5 was tested in six onfarm trials, and the increase in pod yields was up to 48% in kharif (rainy season). A 55-kDa chitinase was purified from the cell-free culture filtrate of GPS 5 by affinity chromatography and gel filtration. Purified chitinase of S. marcescens GPS 5 (specific activity 120 units) inhibited the in vitro germination of P. personata conidia, lysed the conidia, and effectively controlled LLS in greenhouse tests, indicating the importance of chitinolysis in biological control of LLS disease by GPS 5.     

Prevalence,molecular fingerprinting and drug resistance profile of enterovirulent <Emphasis Type="Italic">Escherichia coli</Emphasis> isolates from free-ranging yaks of Tawang district,Arunachal Pradesh,India

Of 273 samples (rectal swab) collected from free-ranging yaks of Tawang district, Arunachal Pradesh, 42 Shiga toxin-producing Escherichia coli (STEC), six enteropathogenic E. coli (EPEC) and 27 enterotoxigenic E. coli (ETEC) strains were isolated. All the STEC and EPEC strains were further investigated for respective stx variants (for STEC only) and additional putative virulence factors. The 27 ETEC strains were also screened for characteristic enterotoxin gene(s) and colonization factors. Occurrence of ETEC was significantly (p < 0.05) higher in the diarrheic yaks and yaks of less than 1 year of age. Majority of enterovirulent E. coli isolates were resistant to amikacin, azithromycin, chloramphenicol, colistin, doxycycline, furazolidone, nalidixic acid, nitrofurantoin, streptomycin and tetracycline. Dendrogram, constructed with molecular fingerprinting profiles obtained from RAPD (Randomly Amplified Polymorphic DNA) and ERIC (Enterobacterial Repetitive Intergenic Consensus) PCR, placed the isolates in different clusters irrespective of their serotypes, virulence gene and drug resistance pattern. Collectively, the study indicates that yaks, being a potential reservoir of multidrug resistant STEC and EPEC, may represent significant risk to public health in this region. Higher recovery of ETEC isolates from yaks with diarrhea points out that ETEC may be a major determinant for repeated occurrence of diarrhea in yaks.     

Integrated effect of population and weed management regimes on weed dynamics,performance, and productivity of basmati rice (<Emphasis Type="Italic">Oryza sativa</Emphasis> L.)

Weeds caused serious problem on yield reduction of basmati rice worldwide. Losses caused by weeds varied from one country to another, depending on the presence of dominant weeds and the control methods practiced by farmers; therefore, suitable plant population and weed management practices should be adopted. Keeping these in mind, a field experiment was carried out during kharif seasons of 2009 and 2010 at crop Research Centre of SVPUA&T, Meerut, India comprising 4 planting geometries, viz. 20, 30, 40, and 50 hills m^?2 as main plot factor, and 5 weed management practices (Butachlor @ 1.0 kg ha^?1, Butachlor @ 1.0 kg ha^?1 fb (followed by) one hand weeding, Butachlor @ 1.0 kg ha^?1 fb Almix @ 4 g ha^?1, two hand weedings and weedy check) in a split plot design with 3 replications. Experimental results revealed that plant population of 50 hills m^?2 proved superior over that of 20 hills m^?2 in respect of weed density, weed dry weight, number of tillers m^?2, yield attributes, grain, straw, and biological yields. The maximum grain yield (29.00 and 31.00 q ha^?1) and straw yield (51.30 and 52.50 q ha^?1) were recorded in 50 hills m^?2 followed by 40 hills m^?2 during 2009 and 2010, respectively. In respect of nitrogen, phosphorus, and potassium removal, a reverse trend was observed: the highest in 20 hills m^?2 followed by 30, 40, and 50 hills m^?2. As far as the weed management practices are concerned, both chemical and mechanical methods of weed control were found superior over weedy check. The lowest weed density, dry weight, and highest weed control efficiency, maximum length of panicle^?1, number of panicle (m²), and 1000-grain weight and grain yield of 30.40 and 32.60 q ha^?1 were recorded with two hand weedings which was at par with Butachlor @ 1.0 kg ha^?1 fb one hand weeding over rest of the weed management practices.     

Morpho-Physiological Responses of Grape Rootstock ‘Dogridge’ to Arbuscular Mycorrhizal Fungi Inoculation Under Salinity Stress

Effects of arbuscular mycorrhizal fungi (AMF) alone or in combination with bacterial consortium (AMF+BC) inoculation prior to induced salinity (NaCl @ 150 or 250 mM) were studied on root growth; plant biomass; leaf area; Na⁺ and K⁺ contents; leaf water potential (Ψ_w); osmotic potential (Ψ_π); photosynthesis rate (P_n); and contents of chlorophyll, phytohormones, and polyamines in the grape rootstock ‘Dogridge’, popular among Indian vine growers. AMF inoculation in the NaCl untreated rootstocks plants increased root growth, root and shoot biomass, and leaf area and improved leaf Ψ_w, Ψ_π, P_n, and chlorophyll content, and also countered the stress-induced decline in the NaCl treated plants. The abscisic acid (ABA), cytokinins, and polyamine-spermidine and spermine contents in the leaves of NaCl untreated or treated were significantly increased by the AMF inoculation. Among the treatments, AMF with BC was relatively more effective than AMF alone with respect to changes in above morpho-physiological characters. The results depicted that AMF (AMF alone or AMF+BC) inoculation significantly improved salinity tolerance of grape rootstock and tolerance is induced by improvements in plant water balance, K⁺:Na⁺ ratio, and P_n, besides distinct accumulations in ABA and polyamines-spermine and spermidine. The above findings have potential in suggesting the AMF usefulness in improving the efficacy of ‘Dogridge’ rootstock in grape cultivation under salt affected soils.