Biochemical Changes in Freshwater Prawn Macrobrachium rosenbergii During Larval Development

Abstract.— Quantitative changes in the protein, lipid and carbohydrate were studied in the early larval stages of developing freshwater prawn Macrobrachium rosenbergii reared under fed and starved conditions to understand the relative importance of these nutrients in energy metabolism of the growing larvae. Larvae obtained from several females were stocked into three 250-L tanks at a density of 30 larvae/L. The feeding regime consisted of newly hatched Artemia nauplii. Protein was always the major organic constituent followed by lipids and then carbohydrates of both fed and starved larvae. Protein levels of both fed and starved larvae increased during development, suggesting an important role in morphogenesis. The decline of lipid during the larval growth that was more rapid for starved larvae, suggests a probable utilization of lipid as the major metabolic source of energy. Carbohydrates formed less than 5 and 2.4% of the larval dry weight of fed and starved larvae, respectively, suggesting their limited role in larval metabolism.     

Nutritional significance of amino acids,vitamins and minerals as nutraceuticals in poultry production and health – a comprehensive review

Nutraceuticals have gained immense importance in poultry science recently considering the nutritional and beneficial health effects of their constituents. Besides providing nutritional requirements to birds, nutraceuticals have beneficial pharmacological effects, for example, they help in establishing normal physiological health status, prevent diseases and thereby improve production performance. Nutraceuticals include amino acids, vitamins, minerals, enzymes, etc. which are important for preventing oxidative stress, regulating the immune response and maintaining normal physiological, biochemical and homeostatic mechanisms. Nutraceuticals help in supplying nutrients in balanced amounts for supporting the optimal growth performance in modern poultry flocks, and as a dietary supplement can reduce the use of antibiotics. The application of antibiotic growth enhancers in poultry leads to the propagation of antibiotic-resistant microbes and drug residues; therefore, they have been restricted in many countries. Thus, there is a demand for natural feed additives that lead to the same growth enhancement without affecting the health. Nutraceuticals substances have an essential role in the development of the animals’ normal physiological functions and in protecting them against infectious diseases. In this review, the uses of amino acids, vitamins and minerals as well as their mode of action in growth promotion and elevation of immune system are discussed.     

Comparison of pregnancy per AI of heifers inseminated with sex-sorted or conventional semen after oestrus detection or timed artificial insemination

The objective of the study was to compare the fertility after using sex-sorted or conventional semen either with oestrus detection (EST) or timed artificial insemination (TAI) in Holstein heifers. Holstein heifers were randomly assigned to one of the following treatments in a 2 × 2 factorial design. Heifers in the EST group were inseminated with sex-sorted (n = 114) or conventional semen (n = 100) after spontaneous or induced oestrus. Heifers in the TAI, subjected to the 5-day Cosynch+Progesterone protocol (GnRH+P4 insertion-5d-PGF_2α+P4 removal-1d-PGF_2α-2d-GnRH+TAI), were inseminated with sex-sorted (n = 113) or conventional semen (n = 88). Statistical analyses were performed using PROC GLIMMIX procedure of SAS 9.4 (SAS Institute Inc., Cary, NC). Overall P/AI was 60.7% for EST and 54.2% for TAI regardless of types of semen and 68.1% for conventional and 48.9% for sex-sorted semen regardless of insemination strategies. Fertility of heifers inseminated with either sex-sorted (53.5%; 44.2%) or conventional (69.0%; 67.0%) semen did not differ between EST and TAI respectively. Besides, the interaction between the semen type and the insemination strategy was not significant for P/AI. The embryonic loss was significantly greater with sex-sorted semen (17.1%) compared to conventional semen (1.6%). There was no sire effect with sex-sorted semen on P/AI (52.6% vs. 46.2%) and embryonic loss (16.4% vs. 18.0%). As expected, sex-sorted semen resulted in more female calves (89.8% vs. 51.6%) than conventional semen. Thus, sex-sorted semen can be used with 5-day Cosynch+Progesterone protocol to eliminate the inadequate oestrus detection and to increase female calves born in dairy heifers.     

Synovial fluid analysis and bacterial findings in arthritic joints of juvenile male camel (Camelus dromedarius) calves

Eighteen synovial fluid samples from 11 male dromedarian calves, 9-12 month old, were analysed cytologically and bacteriologically. Calves were lame and all joints were grossly swollen. The mean +/- SD of total nucleated cell count was 7970 +/- 5000 cells/microl (range 2800-20,000 cells/microl). Polymorphonuclear (PMN) leucocytes were the predominant cell type. The mean +/- SD of absolute and percentages of each cell type were as follows: PMN leucocytes 5518 +/- 3600 cells/microl and 68 +/- 19%, monocytes/macrophages 1600 +/- 1120 cells/microl and 26 +/- 17%, lymphocytes 830 +/- 140 cells/microl and 8 +/- 7%, and red blood cell 350 +/- 130 cells/microl. The mean +/- SD of total protein concentration was 3.5 +/- 1 g/dl (range 2.5-5 g/dl). The most commonly isolated bacteria were non-haemolytic streptococci spp., followed by Arcanobacterium pyogenes and Staphylococcus aureus. No bacterial growth was obtained in eight samples and non-revealed Mycoplasma spp.     

Comparative pharmacokinetics of marbofloxacin in healthy and Mannheimia haemolytica infected calves

The pharmacokinetics of marbofloxacin were investigated in healthy (n=8) and Mannheimia haemolytica naturally infected (n=8) Simmental ruminant calves following intravenous (i.v.) and intramuscular (i.m.) administration of 2 mg kg(-1) body weight. The concentration of marbofloxacin in plasma was measured using high performance liquid chromatography with ultraviolet detection. Following i.v. administration of the drug, the elimination half-life (t(1/2 beta)) and mean residence time (MRT) were significantly longer in diseased calves (8.2h; 11.13 h) than in healthy ones (4.6 h; 6.1 h), respectively. The value of total body clearance (CL(B)) was larger in healthy calves (3 ml min(-1) kg(-1)) than in diseased ones (1.3 ml min(-1) kg(-1)). After single intramuscular (i.m.) administration of the drug, the elimination half-life, mean residence time (MRT) and maximum plasma concentration (C(max)) were higher in diseased calves (8.0, 12 h, 2.32 microg ml(-1)) than in healthy ones (4.7, 7.4 h, 1.4 microg ml(-1)), respectively. The plasma concentrations and AUC following administration of the drug by both routes were significantly higher in diseased calves than in healthy ones. Protein binding of Marbofloxacin was not significantly different in healthy and diseased calves. The mean value for MIC of marbofloxacin for M. haemolytica was 0.1+/-0.06 microg ml(-1). The C(max)/MIC and AUC(24)/MIC ratios were significantly higher in diseased calves (13.0-64.4 and 125-618 h) than in healthy calves (8-38.33 and 66.34-328 h). The obtained results for surrogate markers of antimicrobial activity (C(max)/MIC, AUC/MIC and T > or = MIC) indicate the excellent pharmacodynamic characteristics of the drug in diseased calves with M. haemolytica, which can be expected to optimize the clinical efficacy and minimize the development of resistance.     

Effect of Extraction Variables on the Biodegradable Chelant-Assisted Removal of Toxic Metals from Artificially Contaminated European Reference Soils

Development of aminopolycarboxylate chelants (APCs) having enhanced biodegradability is gaining increasing focus to replace the EDTA and its homologs with those used widely for the ex situ treatment of contaminated soils and are potential eco-threats. The paper reports the chelant-assisted extraction of the toxic metals (Cd, Cu, Pb, and Zn) from the metal-spiked European reference soils (Eurosoil 1 and Eurosoil 4) using biodegradable APCs, namely EDDS, GLDA, and HIDS. The effects of chelant-to-metal molar ratio, solution pH, and metal/chelant stability constants were evaluated, and compared with that of EDTA. The selectivity aptitude of the biodegradable chelants towards the toxic metals was assumed from the speciation calculations, and a proportionate correlation was observed at neutral pH. Pre- and post-extractive solid phase distributions of the target metals were defined using the sequential extraction procedure and dissolution of metals from the theoretically immobilized fraction was witnessed. The effect of competing species (Al, Ca, Fe, Mg, and Mn) concentrations was proven to be minimized with an excess of chelant in solution. The highlight of the outcomes is the superior decontamination ability of GLDA, a biodegradable APC, at minimum chelant concentration in solution and applicability at a wide range of pH environments.     

Dynamics of dissolved oxygen (DO) in ponded water of a paddy field

The transfer of heat and dissolved oxygen (DO) through water is important to understand the phenomenon of ponded water in a paddy soil. The heat from solar radiation is absorbed at the soil surface and transferred into the ponded water by convection. This study clarified the dynamics of DO, as well as the role of convection in water in DO transfer in the ponded water of a paddy field. DO concentration in the ponded water of a paddy field was measured in situ in the daytime and during the night. The results were confirmed in lab-scale model experiments. The DO concentration and temperature profiles in the ponded water of a lab-scale paddy field model were investigated under convective and non-convective conditions using solar radiation and infrared radiation, respectively. Under the ponded condition, solar radiation was absorbed at the soil surface whereas infrared radiation was absorbed at the water surface and thereby convective and non-convective conditions were generated, respectively. The diurnal variation in DO concentration was closely related to the intensity of solar radiation. Oxygen generation by micro-algae and its subsequent circulation by convection resulted in uniform DO concentration profiles, with super-saturated values in the ponded water in the daytime. Eventually oxygen was released to the atmosphere by deaeration until DO in water was depleted to the saturated level. During the night the oxygen moved from the atmosphere into the water surface by reaeration which depends on the oxygen deficit related to saturation. The oxygen deficit is caused by the respiration of microorganisms. The oxygen, that moved from the atmosphere to the water surface, was transferred to the soil surface by convection in the water layer. Thus convection plays an important role in the DO transfer in the ponded water of a paddy field. The DO dynamics is correlated with biological processes in the ponded paddy soil.     

Strawberry Shelf Life,Composition, and Enzymes Activity in Response to Edible Chitosan Coatings

A series of active biodegradable coatings based on chitosan, gelatin, starch, and sorbitol with or without monoterpenes (geraniol and thymol) were prepared and applied on fresh strawberry fruit as postharvest treatments. The coated fruits were inoculated with fungal spores of Botrytis cinerea and stored for 7 days at 4 °C. Decay incidence, weight loss, anthocyanins, total soluble solids (TSS), total soluble phenolics (TSP), polygalacturonase (PGase), pectin-lyase (PLase), antioxidant activity, guaiacol peroxidase (G-POD), polyphenol oxidase (PPO), and catalase (CAT) were elucidated in the fruits of experimental sets and they were compared with that of controls. The coatings showed a significant effect on the development of quality variables, with the additional effect of geraniol and thymol as a function of the polysaccharide matrix. The coatings inhibited decay incidence, reduced weight loss, delayed changes in the contents of anthocyanin, TSS, and total soluble phenolics; inhibited the increase in G-POD and PPO activities; and retarded the reduction in CAT activity. Compared to the controls, all of the coatings had positive effects on the inhibition of cell wall degrading enzymes (PGase and PLase) and among all the tested coatings, T5, chitosan (1%) + starch (1%) + sorbitol (0.5%) + tween (0.05%) + thymol (0.02%) was the best. This formulation showed also the highest antimicrobial activity and the greatest effect on other physiochemical parameters and it can be suggested to use it as a useful coating agent for extending the shelf-life and maintaining quality of strawberry fruit.     

Pantoea: a newly identified causative agent for leaf blight disease in rice

Journal of Plant Diseases and Protection - Leaf blight is one of the most serious threats to rice agroecosystems worldwide, and the yield reduction due to this disease can be as high as 70%. For...     

Effects of AG1 and AG2 QTLs on Nonstructural Carbohydrate and Seed Management Options for Rice Seedling Growth and Establishment under Flooding Stress

Rice (Oryza sativa) plants acquired excess photosynthates in the form of nonstructural carbohydrates (NSCs) in their stems and grain. Despite keen interest in rice NSC, the dynamics of NSC accumulation, translocation and re-accumulation have not yet been well investigated. AG1 and AG2 QTLs associated with flooding tolerance through catalyzing starch into soluble sugar in germinating seeds. Here we conducted three experiments, greenhouse and field to lay the groundwork for large-scale diversity studies on grain NSC and some agronomic traits under direct-seeded rice (DSR) system, using elite lines incorporating AG1, AG2 and AG1-AG2 QTLs into the popular varieties PSB Rc82 and Ciherang-Sub1 along with the donors Kho Hlan On (AG1) and Ma-Zhan Red (AG2). In germinating seedlings, soluble sugars increased, while starch concentration decreased gradually especially in the tolerant checks and AG1-AG2 introgression lines under flooded soil. Soluble sugar accumulation in stem started to increase from the vegetative stage and peaked at the panicle initiation stage then gradually decreased towards the maturity stage. But Sub1-AG lines had higher sugar and starch concentrations at different growth stages than other genotypes in wet season 2016 and dry season 2017. Plant survival rate was positively correlated with the stem NSC at the early vegetative stage (21 days after sowing), and stem NSC was positively associated with plant height at different growth stages. Among the tested seeding rate, the most suitable seeding rate, 4 g/m² with shallow burial depth (0.5 cm), resulted in better seedling establishment, relatively higher seedling vigor index and higher leaf area index under flooding in DSR system. Introgression of AG1-AG2 QTLs had no any negative impact on nonstructural carbohydrate, germination rate, and growth and biomass production.