Multiparent advanced generation inter-cross(MAGIC)populations improve the accuracy of quantitative trait loci mapping compared to biparental populations by increasing diversity and reducing linkage disequilibrium betw...Multiparent advanced generation inter-cross(MAGIC)populations improve the accuracy of quantitative trait loci mapping compared to biparental populations by increasing diversity and reducing linkage disequilibrium between variants.Here we describe the development of two MAGIC populations derived from a cross of 11 founder lines from the INTA(National Institute for Agricultural Technology in Argentina)sunflower breeding program.The founder lines are fertility maintainer inbred lines that exhibit genetic diversity in several traits,including flowering cycle,plant architecture,disease resistance,oil content and oil quality.The crossing scheme applied follows the design of two-way,four-way and eight-way crosses with a modification to increase the number of recombinations and shorten the linkage disequilibrium.Phenotyping a subset of F_(2)families and F_5 lines for different traits shows an increase in the diversity of the analyzed traits compared to the parental lines.In addition,we identified lines with transgressive segregation for Sunflower Verticillium Wilt resistance.These results confirm that the MAGIC populations will serve as unique genetic and genomic resources to better characterize the genetics of complex traits and identify potentially superior alleles for sunflower breeding.It will also enrich the gene pool of fertility maintainers(A/B line)of the sunflower germplasm and facilitate the introduction of new breeding methods to select female parents for use in AxR combinations to obtain superior sunflower hybrids.展开更多
To improve crop yields,global food production needs sustainable agronomic tools like Plant Growth-Promoting Rhizobacteria(PGPR).Region-adapted PGPR strains are crucial to increasing peanut production.Argentina is the ...To improve crop yields,global food production needs sustainable agronomic tools like Plant Growth-Promoting Rhizobacteria(PGPR).Region-adapted PGPR strains are crucial to increasing peanut production.Argentina is the seventh-largest peanut producer,and Cordoba is the main region with 250,000 ha(75%of the total sowing area).This study aimed to isolate,identify,and characterize the biocontrol and growth promotion capacity of PGPR strains belonging to the Bacillus and Pseudomonas genera.The strains were tested against Sclerotinia minor,Sclerotium rolfsii,Fusarium verticillioides,and Aspergillus flavus for biocontrol assays.For growth promotion,pot trials used two peanut cultivars,ASEM 400 INTA and Granoleico,under 40%and 60%field capacity under two water regimes.The isolated strains were Bacillus velezensis,B.subtilis,B.tequilensis,B.safensis,B.altitudinis,and Pseudomonas psychrophila.These strains demonstrated in-vitro phosphorus solubilization,nitrogen fixation,ammonification,nitrification,enzyme releasing,phytohormones production,and high biocontrol capacity of over 75%.SC6 and RI3(both B.velezensis)and P10(P.psychrophila)exhibited outstanding performance.They significantly promoted peanut root biomass by more than 50%and leaf area by 30%,with increased chlorophyll content index and leaf relative water content,particularly under water stress conditions(40%field capacity).According to the results,RI3,SC6,and P10 could be classified as PGPR,which supports the results obtained in other field studies with these same microorganisms.Future investigations should prioritize the development of industrial formulations to assess their effectiveness in alternative crops and to incorporate them into other agricultural practices.展开更多
Background:The European rabbit(Oryctolagus cuniculus L.1758)was introduced into different regions of the world,generating significant trade‑offs that critically impacted native vegetation.Here,we evaluate the rabbit’...Background:The European rabbit(Oryctolagus cuniculus L.1758)was introduced into different regions of the world,generating significant trade‑offs that critically impacted native vegetation.Here,we evaluate the rabbit’s forage intakes in three vegetation types(forests,shrublands,and grasslands)along the four seasons in a temperate forest landscape in Southern Patagonia and discuss the potential threats over native vegetation.We formulated the following questions:(i)what is the forage offer at each vegetation type?(ii)what is the rabbit’s forage intake and how it varied across the seasons along the year?and(iii)which vegetation types and plant life forms were more used according to the rabbit’s forage intakes?Methods:We censused understory vegetation to characterize the forage offer at each vegetation type and determined seasonal dietary intakes using microhistological analysis of pellets.The plant species identified in the field were grouped according to life form classes(tree regeneration,shrubs,forbs,graminoids,orchids,ferns,bryophytes,and hemiparasites).Data were analysed through uni‑and multi‑variate analyses,determining relationships between forage offer and the rabbit’s forage intakes.Results:Forage intakes revealed changes in plant life form consumption across vegetation types,where intake pressure was considerably different for tree regeneration(p=0.001),graminoids(p=0.001),and hemiparasites(p=0.001).Besides,significant changes in consumption among seasons were detected for shrubs(p=0.001),ferns(p=0.030),and hemiparasites(p=0.002).Although many species play an important role in the rabbit’s forage intake networks(e.g.,Chiliotrichum diffusum,Holcus lanatus),the strongest intake linkages were found in exotic grasses(e.g.,Poa pratensis and Festuca sp.),native hemiparasites(e.g.,Misodendrum sp.),native shrubs(e.g.,Empetrum rubrum),and native trees(e.g.,Nothofagus sp.).The summer and autumn seasons presented higher intake compared to the winter and spring seasons.Furthermore,hemiparasites intake(e.g.,Misodendrum sp.)suggests that rabbits utilize different forage sources depending on the vegetation types.Conclusions:Rabbits regularly inhabit the forest,even though it is not their preferred vegetation type to live.Rabbit management entails isolating regions that are more favourable to intake and emphasizing the year’s season for rabbit control efforts.展开更多
Management under ecological schemes and increasing habitat heterogeneity,are essential for enhancing biodiversity in vineyards.Birds provide several contributions to agriculture,for example pest control,recreation and...Management under ecological schemes and increasing habitat heterogeneity,are essential for enhancing biodiversity in vineyards.Birds provide several contributions to agriculture,for example pest control,recreation and enhancing human mental health,and have intrinsic value.Birds are also ideal model organisms because they are easy to survey,and species respond differently to agricultural land use at different scales.Vegetated borders of crops are key for many species of birds,and distance to the border have been found to be an important factor in vineyard-dominated agroecosystems.We evaluate if there are differences in the bird assemblage,between the interior compared to borders within vineyards,using a hierarchical community occupancy model.We hypoth-esized that occupancy of birds is greater in environments with greater heterogeneity,which in this study was considered to be contributed by the proximity to vegetated corridors.We expected that vineyard borders close to corridors will have higher bird occupancy than the center of the vineyard.The research was conducted in three vineyards with biodiversity-friendly management practices,in Gualtallary,Mendoza,Argentina.Bird surveys were conducted over three breeding seasons from 2018 to 2020.Occupancy and richness of the bird community was more closely associated with the borders adjacent to the corridors than with the interior of the vineyards,as we initially predicted,although the assemblage of birds did not differ much.More than 75%of the registered species consume exclusively or partially invertebrates.Biodiversity-friendly management and ecological schemes,together with vegetated corridors provide multiple benefits for biodiversity conservation.These ap-proaches not only minimize the use of agrochemicals but also prioritize soil cover with spontaneous vegetation,which supports a diverse community of insectivorous bird species,potentially contributing to pest control.展开更多
Semiarid Patagonia represents 25%of the rangeland area in Argentina,and sheep overgrazing has degraded about a third of it in the past.In this century,depleted domestic stocks have mostly stabilized,but Guanaco popula...Semiarid Patagonia represents 25%of the rangeland area in Argentina,and sheep overgrazing has degraded about a third of it in the past.In this century,depleted domestic stocks have mostly stabilized,but Guanaco populations have grown.These native camelids share habitat and diets with sheep,but their effect on vegetation is poorly understood and has long been debated.We set up an exclusion experiment in Monte León and Cañadón Vaca,a semiarid shrubland grassland in southern Patagonia,currently grazed only by guanacos.Vegetation baselines were studied in 2016 in twelve plots,and half of them were protected from guanaco grazing.Thirty-six plots were cleared to study revegetation.Vegetation was reassessed in 2021,and changes were evaluated using a paired t-test.Within protected plots,vegetation cover increased,bare soil diminished,and vegetated patches grew in size,but the density of the patch-interpatch arrangement did not change.Biodiversity,measured by richness and the Shan-non-Wiener(SW)index,grew significantly.Nutrient recycling increased,as did the Stability and Infiltration Land Function indexes,although these last differences were not significant.Vegetation cover under guanaco grazing also increased,mainly due to the growth of dwarf shrubs,a typical tendency in sheep grazing-induced transitions in the region.Vegetated patches under grazing fragmented,resulting in smaller patches and denser patch struc-tures,while diversity and land function indexes remained unchanged.Young plants established in cleared plots without guanacos showed higher cover density and individual size.These effects are similar to those observed in numerous experimental sheep exclosures.Guanaco grazing may thus prevent restoration and contribute to the generalized land degradation processes that overgrazing has been causing in Patagonia for over a century.展开更多
Ferroptosis,an iron-dependent cell death:Ferroptosis is a type of regulated necrosis,characterized by redox-active iron accumulation and increased free radical production derived by Fenton chemistry,that triggers oxid...Ferroptosis,an iron-dependent cell death:Ferroptosis is a type of regulated necrosis,characterized by redox-active iron accumulation and increased free radical production derived by Fenton chemistry,that triggers oxidation of polyunsaturated fatty acids in phospholipids,loss of cellular membranes integrity,and leakage of intracellular contents.展开更多
Beneficial microbes can improve soil health by promoting soil structure,nutrient cycling,and disease suppression.In addition,a wide array of rhizospheric microbes are responsible for producing metabolically active comp...Beneficial microbes can improve soil health by promoting soil structure,nutrient cycling,and disease suppression.In addition,a wide array of rhizospheric microbes are responsible for producing metabolically active compounds including various types of plant growth regulators.So,microbial biodiversity studies could contribute to the improvement of agricultural practices in deprived areas,such as the Pampean semiarid region.The vast majority of studies conducted on endophytic microorganisms have focused on intensive crop legume species.In contrast,little attention has been paid to microorganisms of native legumes,whose ecology is not directly affected by human action.In this study,endophytic microorganisms isolated from root nodules of a selected native legume of the genus Rhynchosia were characterized.Viable isolates were studied with a focus on their plant growth-pro-moting rhizobacteria(PGPR)properties.Considering the edaphic characteristics of the Pampean semiarid region,the isolates obtained were evaluated for their ability to grow under three salt stress conditions(50,100,and 200 mM NaCl)and four different pH values(6,7,8,and 9).Based on their PGPR activities,the selected strains were phylogenetically grouped using BOX-PCR.The results showed great variability among the isolates in terms of the characteristics studied.Native legumes manifested a wide endophytic variability and remarkable perfor-mance in PGPR activities.We conclude that they could be used as potential bioinoculants for legume cultivation,an excellent alternative to the use of chemical fertilizers that currently pollute the environment.展开更多
This experiment aimed to evaluate the effect of calcium salts of linseed oil (rich in alpha-linolenic acid (ALA, C18:3n-3) on metabolic and reproductive traits in high-producing dairy cows under grazing. Thirty-six Ho...This experiment aimed to evaluate the effect of calcium salts of linseed oil (rich in alpha-linolenic acid (ALA, C18:3n-3) on metabolic and reproductive traits in high-producing dairy cows under grazing. Thirty-six Holstein dairy cows were randomly assigned, in a complete block design, to receive ALA supplementation (0.85 kg∙day−1 of calcium salts of linseed oil) or to remain as untreated control (CON). The concentrate was formulated to offer the same amount of energy across treatments (CON cows received an extra kg of corn to compensate for the higher energy density of ALA treatment). A PMR + Alfalfa pasture was offered to all cows at the same time. A fixed time artificial insemination (FTAI) at 80 DIM, preceded by a Presynch plus Ovsynch protocol was implemented for the first service and later, on return to estrus, heat detection and artificial insemination (AI) were performed. Pregnancy diagnosis was checked at 30, 42, 60, and 90 d after AI. Blood and milk samples were taken biweekly. Treatment affected plasma cholesterol concentration (160.36 vs. 186.70 mg∙dl−1, p = 0.03, for ALA and CON, respectively) and on size of corpus luteum (CL, 17.6 vs. 13.7 mm, p = 0.02, for ALA and CON, respectively). Supplementation tended (p = 0.136) to increase conception rate by 200 DIM (81.69% vs. 55.43% in ALA and CON cows, respectively). However, treatment had no effect (p > 0.05) on body weight (BW), body condition score (BCS), and circulating levels of beta-hydroxybutyrate (BHBA), glucose, insulin, growth hormone (GH) and insulin-like growth factor (IGF-I). Our results suggest that supplementation with calcium salts of linseed oil could enhance ovarian function without affecting energy metabolism in early lactation dairy cows.展开更多
The Puna grasslands support grazing systems that produce meat and wool in multi-species herds,especially from llama(Lama glama)and sheep.However,it is yet unknown whether grazing pressure can modify grassland structur...The Puna grasslands support grazing systems that produce meat and wool in multi-species herds,especially from llama(Lama glama)and sheep.However,it is yet unknown whether grazing pressure can modify grassland structure and Plant Functional Types diversity and cover in Puna grasslands.We analyzed the relationship between grazing pressure and Plant Functional Types by comparing transects located near stockyards(high grazing pressure)and far from them(low pressure)and by evaluating the relationship between the Plant Functional Types cover to a Grazing Pressure Index(GPI).This index incorporates the heterogeneity of traditional pastoral management.At two ecological sites(Ciénego and Tolar),we sampled paired transects(near-far).Plots near and far from corrals were similar in all the variables measured except for plots in Tolar,which tend to have higher total cover,possibly due to fecal fertilization near stockyards.Furthermore,we recorded an increase in total cover and grass cover at higher GPI in Ciénego,while in Tolar we found lower values of total cover and herbaceous dicotyledonous cover at intermediate intensities of GPI.The only negative relationship found was the cover of clonal and non-clonal shrubs,possibly explained by the greater use of these shrubs as firewood near stockyards.In summary,our study does not show important changes in Plant Functional Types as a function of grazing pressure in the studied grasslands probably because grazing pressure is diluted or diminished when livestock rotates in different areas and grazing durations vary.Finally,the long grazing history with which the Puna has evolved could also contribute to the co-structuration between native vegetation and livestock farming.展开更多
Anaerobic digestion is a process that is widely used for the treatment of organic wastes. The digestate can be used as a soil amendment or crop fertiliser. The aims of our work were to evaluate 1) the physicochemical ...Anaerobic digestion is a process that is widely used for the treatment of organic wastes. The digestate can be used as a soil amendment or crop fertiliser. The aims of our work were to evaluate 1) the physicochemical composition and pathogen content in a digestate from poultry manure, according to international regulations, and 2) the effect of its soil application on the major chemical and biological soil properties and on the growth of Lactuca sativa. The experiment consisted of two groups of pots(with and without crop). Treatments applied to each group were as follows: low and high doses of digestate and inorganic fertiliser, and no application(control)(low dose: 70 kg nitrogen(N) ha^(-1) and 21 kg phosphorus(P) ha^(-1); high dose: 210 kg N ha^(-1) and 63 kg P ha^(-1)). Soil samples were taken 7 and 34 d(harvest) after treatment applications. Heavy metal and pathogen contents in the digestate were below the upper limit values. Despite the high pH and electrical conductivity values of the digestate, both soil parameters presented acceptable values for crop growth. Although there were no initial increases in total inorganic N and available P in soil with digestate application, an increase in the fresh weight of crop was observed with the high dose application. This is probably associated with the slow nutrient release from the digestate during the development of the crop. Changes in the microbial community were temporary and occurred at the initial sampling stage of the experiment.展开更多
Rapid emergence and a vigorous growth prevent the seed tubers from infections by soil microbes and allow a rapid interception of solar radiation. In this work, the effect of the potassium phosphites (KPhi) applied to ...Rapid emergence and a vigorous growth prevent the seed tubers from infections by soil microbes and allow a rapid interception of solar radiation. In this work, the effect of the potassium phosphites (KPhi) applied to seed tubers of two potato cultivars on crop emergence and early growth was studied. Two experiments were performed under greenhouse and field conditions. Emergence of plants, leaf area, dry matter and the number of primary stems were measured in both experiments. Furthermore, mycorrhizal colonization was also measured on roots under field conditions. The application of KPhi reduced the period between planting and emergence, and increased leaf area and dry matter. The ratio between dry matter of aerials and underground organs was not affected by KPhi. Indigenous mycorrhizal colonization increased after KPhi application to seed tubers. These results confirm the benefit of the application of KPhi to seed tubers on early plant growth and suggest that their application in crop production would be advantageous.展开更多
Forty multiparous Holstein cows in early lactation (66 ± 19 days) were assigned to one of four treatments that consisted in different ratios of total mixed rations (TMR) and pasture at 100% TMR (T0), 75:25 (T1) 5...Forty multiparous Holstein cows in early lactation (66 ± 19 days) were assigned to one of four treatments that consisted in different ratios of total mixed rations (TMR) and pasture at 100% TMR (T0), 75:25 (T1) 50:50 (T2) and 25:75 (T3) over 9 weeks in autumn-winter. Measures of rumen parameters and digestion were performed on 4 additional Holstein cows in late lactation (287 days postpartum) fitted with permanent ruminal fistulae and producing 22.6 (±5.4) kg milk in a 4 × 4 Latin Square design. In T1 to T3 cows were taken to the grazing plot once they finished the pre-planned TMR intake and pasture was offered at 2 times the expected forage DM intake. Milk was analyzed for chemical composition, milk fatty acid (FA) profile and antioxidant compounds. The cows were individually weighed and body condition score (BCS) was determined. After the morning milking, blood samples were taken every 2 weeks and plasma was analyzed for glucose, urea, non-esterified fatty acids (NEFA), insulin, growth hormone (GH) and insulin-like growth factor (IGF-I). Herbage mass in pre grazing strips of pasture averaged 2540 ± 343 kg DM/ha. As TMR intake increased, production variables increased linearly excepting milk fat (3.88 g/100g) and milk protein (3.43 g/100g) contents that were not affected. Milk yield (kg/cow/d) resulted maximal in T0 (34.2) and linearly decreased (p 3-N concentration resulted higher in treatments with higher proportion of pasture. Kinetic parameters of DM and NDF digestion from pasture or corn silage were not affected. Milk FA profile and milk antioxidant quality showed unfavorably changes as TMR increased by a decrease in rumenic and linolenic acids and content of antioxidant vitamins, without effect on the atherogenicity index. Results suggested a depressing effect of the pasture on total DM and energy intake probably explained by qualitative deficiencies chemical composition of the forage and/or factors that affect animal behavior that may induce losses in body condition of high yielding dairy cows.展开更多
Rapid and sensitive reversed phase high performance liquid chromatography (RP-HPLC) and ultra performance liquid chromatography (RP-UPLC) method with UV detection has been developed and validated for quantification of...Rapid and sensitive reversed phase high performance liquid chromatography (RP-HPLC) and ultra performance liquid chromatography (RP-UPLC) method with UV detection has been developed and validated for quantification of parathyroid hormone (PTH) in presence of meta-cresol as a stabilizer in a pharmaceutical formulation.Chromatography was performed with mobile phase containing 0.1% Trifluoroacetic acid (TFA) in MilliQ water and 0.1% TFA in acetonitrile with gradient program and flow rate at 0.3 mL/min for HPLC and 0.4 mL/min for UPLC.Quantification was accomplished with internal reference standard (qualified against innovator product and National Institute for Biological Standards and Control (NIBSC) standard).The methods were validated for linearity (correlation coefficient 0.99),range,accuracy,precision and robustness.Robustness was confirmed by considering three factors;mobile phase composition,column temperature and flow rate/age of mobile phase.Intermediate precision was confirmed on different equipments,different columns and on different days.The relative standard deviation (RSD) (<2% for RP-HPLC and <1% for UPLC,n=30) indicated a good precision.Retention time was found about 17 min and 2 min by HPLC and UPLC methods,respectively.Both methods are simple,highly sensitive,precise and accurate and have the potential of being useful for routine quality control.展开更多
This paper describes a method for mesh adaptation in the presence of intersections, such as wing-fuselage. Automatic optimization tools, using Computational Fluid Dynamics（CFD） simulations, face the problem to adapt...This paper describes a method for mesh adaptation in the presence of intersections, such as wing-fuselage. Automatic optimization tools, using Computational Fluid Dynamics（CFD） simulations, face the problem to adapt the computational grid upon deformations of the boundary surface. When mesh regeneration is not feasible, due to the high cost to build up the computational grid, mesh deformation techniques are considered a cheap approach to adapt the mesh to changes on the geometry. Mesh adaptation is a well-known subject in the literature; however, there is very little work which deals with moving intersections. Without a proper treatment of the intersections,the use of automatic optimization methods for aircraft design is limited to individual components.The proposed method takes advantage of the CAD description, which usually comes in the form of Non-Uniform Rational B-Splines（NURBS） patches. This paper describes an algorithm to recalculate the intersection line between two parametric surfaces. Then, the surface mesh is adapted to the moving intersection in parametric coordinates. Finally, the deformation is propagated through the volumetric mesh. The proposed method is tested with the DLR F6 wing-body configuration.展开更多
Glyphosate is the most used herbicide in Argentina, accounting for 62% of the commercialized pesticides on the market. It is used as a weed controller in no-till systems, and it is also applied to various genetically ...Glyphosate is the most used herbicide in Argentina, accounting for 62% of the commercialized pesticides on the market. It is used as a weed controller in no-till systems, and it is also applied to various genetically modified crops ( e.g., soybean, corn, and cotton). Although it has a high solubility in water, it tends to adsorb and accumulate in agricultural soils. The main objectives of this work were to compare the dissipation of glyphosate and the accumulation of its metabolite aminomethylphosphonic acid (AMPA) over time in three soils from agricultural areas of Argentina under long-term management with no-till (NT) and conventional tillage (CT) practices. There were no differences in dissipation between NT and CT, indicating that the glyphosate-degrading microflora was not modified by the different tillage managements. Moreover, tillage practices did not alter the general soil properties;therefore, glyphosate bioavailability was not affected by NT or CT practice. Forty percent of the applied glyphosate was degraded within the first three days in all soils, indicating a fast initial dissipation rate. However, the dissipation rate considerably decreased over time, and the degradation kinetics followed a bi-exponential (or two-compartment) kinetic model. No differences were found between tillage practices. Dissipation was not related to the microbial activity measured as soil respiration. The fast decrease in the concentration of glyphosate at the beginning of the dissipation study was not reflected in an increase in the concentration of AMPA. The estimated half-lives for glyphosate ranged between 9 and 38 d. However, glyphosate bioavailability decreases over time, as it is strongly adsorbed to the soil matrix. This increases its residence time, which may lead to its accumulation in agricultural soils.展开更多
The aim of the study was to determine the effect of three levels of energy concentrate intake on dry matter (DM) and energy intake, milk yield and composition, rumen environment and pasture neutral detergent fiber (ND...The aim of the study was to determine the effect of three levels of energy concentrate intake on dry matter (DM) and energy intake, milk yield and composition, rumen environment and pasture neutral detergent fiber (NDF) digestion. Twelve Holstein multiparous cows in early lactation (69.0 ± 5 days postpartum) producing 32.8 (±4.0) kg milk were assigned to three treatments at (kg/cow day) 3.5 (T3.5), 7.0 (T7.0) and 10.5 (T10.5) kg concentrate in a 3 × 3 Latin Square design. Parameters of ruminal environment and neutral detergent fiber (NDF) digestion were obtained using 3 additional rumen cannulated cows. Concentrate was composed (as fed) by corn grain (68%), soybean meal (22%), wheat bran (8%) and a vitamin-mineral premix including monensin and thoroughly consumed. Yields (kg/cow day-1) of milk, 4% fat corrected milk (4% FCM 4%) and energy corrected milk (ECM) resulted higher (p p -1 without effects on yield of milk fat. Concentrations (g/100 g) of milk fat (3.19), protein (2.97), total solids (11.75), non-fat solids (8.60) and casein (2.40) did not differ. Milk lactose content (g/100 g) was linearly increased (p p p p p < 0.05) in T3.5 due to the increase in acetate and butyrate while the acetate: Propionate ratio remained unchanged. Pasture NDF digestion was affected as concentrate intake increased. To increase milk protein yield and reduce concentrations of N-NH3 in rumen and milk, feeding an energy concentrate at 41% of total DM intake resulted an effective tool.展开更多
Dear Editor,Infectious bursal disease virus（IBDV）causes infectious bursal disease,a highly contagious immunosuppressive disease that affects young chickens and causes economic losses in the poultry industry worldwid...Dear Editor,Infectious bursal disease virus（IBDV）causes infectious bursal disease,a highly contagious immunosuppressive disease that affects young chickens and causes economic losses in the poultry industry worldwide.IBDV replicates mainly in actively dividing B lymphocytes within the bursa of Fabricius（BF）,leading to immunosuppression in affected flocks（Mahgoub et al.,2012）.Viral protein 2（VP2）,展开更多
The objective was to reduce saturated fatty acids (SFA) and increase conjugated linoleic acid (CLA, cis-9, trans-11 C18:2), α-linolenic (cis-9, cis-12, cis-15 C18:3) and docosahexaenoic (DHA, C22:6) contents in milk ...The objective was to reduce saturated fatty acids (SFA) and increase conjugated linoleic acid (CLA, cis-9, trans-11 C18:2), α-linolenic (cis-9, cis-12, cis-15 C18:3) and docosahexaenoic (DHA, C22:6) contents in milk from confined dairy cows in order to promote a healthier option. The work was carried out in a commercial farm (Talar) located in Laguna del Sauce, Maldonado (Uruguay). Twenty four cows were assigned to one of two treatments (12 cows per treatment) over a 6 weeks experimental period. Treatments consisted in a control total mixed ration (C-TMR) without supplementary lipids (L) or the same TMR with the addition of 0.144 kg/cow·day of algae and 0.72 kg/cow·day of soybean oil (L-TMR). Chemical composition of the TMR (44.27% DM) averaged 15.94% for crude protein (CP), 38.20% neutral detergent fiber (NDF), 20.36% acid detergent fiber (ADF), 5.56% fat, 5.30% ash and 28.6% nonstructural carbohydrate (NSCH) with 1.81 Mcal/kg of net energy for lactation (NEL). After 39 days of feeding, individual milk samples were collected during three consecutive days. From the total milk collected, 20 ml were immediately used for chemical composition (Milko Scan) and 80 ml for analysis for milk FA profile. From week 3 onwards, milk production (kg/cow·day) resulted higher (P P P = 0.43) on milk protein content (C-TMR = 3.20;L-TMR = 3.07 g/100g). Milk lactose (C-TMR = 4.86, L-TMR = 4.69 g/100g) and urea nitrogen contents (C-TMR = 21.18, L-TMR = 17.33 g/100g) tended (P cow·day, P 12:0 to C16:0 FA averaging 45.19 in C-TMR and 34.74 g/100g in L-TMR (P P 18:1 trans-9) (0.23) and C18:1 trans-10 (0.44) FA increased (P trans-11 C18:1, VA) increased from 1.08 in C-TMR to 2.56 g/100g of FA in L-TMR (P cis-9, trans-11 C18:2) increased (127%) from 0.62 in C-TMR to 1.41 g/100g FA in L-TMR milk. Content of α-linolenic acid resulted 20% higher (P P cis-9 C18:1) resulted higher (P α-linolenic).展开更多
The Gulf of Cadiz is situated geologically at the Gibraltar Arc, the westernmost arc of the Alpine- Himalayan orogenic belt. Based on extensive previous studies that include swath bathymetry, multi-channel and very hi...The Gulf of Cadiz is situated geologically at the Gibraltar Arc, the westernmost arc of the Alpine- Himalayan orogenic belt. Based on extensive previous studies that include swath bathymetry, multi-channel and very high-resolution seismic reflection, gravime- try, magnetism, heat flow probes, and underwater photography surveys, more than 500 polymetallic nodules were collected at water depths ranging from 850 to 1000 m, associated with hydrocarbon-derived carbonate chimneys, slabs, and crusts. Nodules show a wide range of sizes, densities, weights and mor- phologies. Nodules are composed of multiple milli- metre-thick layers of Fe and Mn oxyhydroxides sur- rounding a nucleus composed of Early-Middle Mio- cene plastic marls, which were expulsed from underly- ing units by fluid venting. Nodules show a high mean abundance of Fe （39.03%）, moderate Mn （5.84%）,展开更多
Increased levels of stress hormones in the muscle could lead to post mortem metabolic/structural modiifcations that could be relfected on meat quality. The present study investigated the metabolic effect of either adr...Increased levels of stress hormones in the muscle could lead to post mortem metabolic/structural modiifcations that could be relfected on meat quality. The present study investigated the metabolic effect of either adrenaline or cortisol injected into lambs in order to obtain an animal model of acute stress. Results showed that adrenaline or cortisol injection lead to glucose metabolism and muscle temperature increase. Muscle pH immediately post mortem was affected by adrenaline treatment. Water holding capacity （WHC） of fresh muscle, ifnal muscle pH and temperature registered at 24 h post mortem were not affected by injected hormones. Hardness and adhesiveness of LD muscle evaluated 3 d post mortem tended to increase as a result of adrenaline or cortisol injection. Results demonstrated that injected hormones were able to affect the post mortem muscle biochemistry and the pH/T curve independently of ifnal muscle pH.展开更多
基金supported by a doctoral grant from the National Scientific and Technical Research Council(Consejo Nacional de Investigaciones Científicas y T ecnicas,CONICET)the National Institute of Agricultural Technology(INTA)+1 种基金by projects funded by INTA(CP_2019–2023 I-114,I-127,I-090/2023–2025 I-111,I-87)Agencia Nacional de Promocio n Científica y T ecnica(PICT 2017N?2523)。
文摘Multiparent advanced generation inter-cross(MAGIC)populations improve the accuracy of quantitative trait loci mapping compared to biparental populations by increasing diversity and reducing linkage disequilibrium between variants.Here we describe the development of two MAGIC populations derived from a cross of 11 founder lines from the INTA(National Institute for Agricultural Technology in Argentina)sunflower breeding program.The founder lines are fertility maintainer inbred lines that exhibit genetic diversity in several traits,including flowering cycle,plant architecture,disease resistance,oil content and oil quality.The crossing scheme applied follows the design of two-way,four-way and eight-way crosses with a modification to increase the number of recombinations and shorten the linkage disequilibrium.Phenotyping a subset of F_(2)families and F_5 lines for different traits shows an increase in the diversity of the analyzed traits compared to the parental lines.In addition,we identified lines with transgressive segregation for Sunflower Verticillium Wilt resistance.These results confirm that the MAGIC populations will serve as unique genetic and genomic resources to better characterize the genetics of complex traits and identify potentially superior alleles for sunflower breeding.It will also enrich the gene pool of fertility maintainers(A/B line)of the sunflower germplasm and facilitate the introduction of new breeding methods to select female parents for use in AxR combinations to obtain superior sunflower hybrids.
基金the Universidad Nacional de Co rdoba,Argentina,and the Secretaría de Cienciay Tecnología (UNC,SECyT) for the financial support of the CONSOLIDAR 2018–2022 project‘EFECTO DE LOS MICROORGANISMOS PROMOTORES DEL CRECIMIENTO SOBRE LA ECOFISIOLOGíA Y EL CONTROL DE ENFERMEDADES EN EL CULTIVO DE MANí.'the Consejo Nacional de Investigaciones Científicas y Técnicas(CONICET) for the doctoral fellowshipthe University of Córdoba (Spain) for the support provided through the “Plan Propio de Investigación” 2020–2024。
文摘To improve crop yields,global food production needs sustainable agronomic tools like Plant Growth-Promoting Rhizobacteria(PGPR).Region-adapted PGPR strains are crucial to increasing peanut production.Argentina is the seventh-largest peanut producer,and Cordoba is the main region with 250,000 ha(75%of the total sowing area).This study aimed to isolate,identify,and characterize the biocontrol and growth promotion capacity of PGPR strains belonging to the Bacillus and Pseudomonas genera.The strains were tested against Sclerotinia minor,Sclerotium rolfsii,Fusarium verticillioides,and Aspergillus flavus for biocontrol assays.For growth promotion,pot trials used two peanut cultivars,ASEM 400 INTA and Granoleico,under 40%and 60%field capacity under two water regimes.The isolated strains were Bacillus velezensis,B.subtilis,B.tequilensis,B.safensis,B.altitudinis,and Pseudomonas psychrophila.These strains demonstrated in-vitro phosphorus solubilization,nitrogen fixation,ammonification,nitrification,enzyme releasing,phytohormones production,and high biocontrol capacity of over 75%.SC6 and RI3(both B.velezensis)and P10(P.psychrophila)exhibited outstanding performance.They significantly promoted peanut root biomass by more than 50%and leaf area by 30%,with increased chlorophyll content index and leaf relative water content,particularly under water stress conditions(40%field capacity).According to the results,RI3,SC6,and P10 could be classified as PGPR,which supports the results obtained in other field studies with these same microorganisms.Future investigations should prioritize the development of industrial formulations to assess their effectiveness in alternative crops and to incorporate them into other agricultural practices.
文摘Background:The European rabbit(Oryctolagus cuniculus L.1758)was introduced into different regions of the world,generating significant trade‑offs that critically impacted native vegetation.Here,we evaluate the rabbit’s forage intakes in three vegetation types(forests,shrublands,and grasslands)along the four seasons in a temperate forest landscape in Southern Patagonia and discuss the potential threats over native vegetation.We formulated the following questions:(i)what is the forage offer at each vegetation type?(ii)what is the rabbit’s forage intake and how it varied across the seasons along the year?and(iii)which vegetation types and plant life forms were more used according to the rabbit’s forage intakes?Methods:We censused understory vegetation to characterize the forage offer at each vegetation type and determined seasonal dietary intakes using microhistological analysis of pellets.The plant species identified in the field were grouped according to life form classes(tree regeneration,shrubs,forbs,graminoids,orchids,ferns,bryophytes,and hemiparasites).Data were analysed through uni‑and multi‑variate analyses,determining relationships between forage offer and the rabbit’s forage intakes.Results:Forage intakes revealed changes in plant life form consumption across vegetation types,where intake pressure was considerably different for tree regeneration(p=0.001),graminoids(p=0.001),and hemiparasites(p=0.001).Besides,significant changes in consumption among seasons were detected for shrubs(p=0.001),ferns(p=0.030),and hemiparasites(p=0.002).Although many species play an important role in the rabbit’s forage intake networks(e.g.,Chiliotrichum diffusum,Holcus lanatus),the strongest intake linkages were found in exotic grasses(e.g.,Poa pratensis and Festuca sp.),native hemiparasites(e.g.,Misodendrum sp.),native shrubs(e.g.,Empetrum rubrum),and native trees(e.g.,Nothofagus sp.).The summer and autumn seasons presented higher intake compared to the winter and spring seasons.Furthermore,hemiparasites intake(e.g.,Misodendrum sp.)suggests that rabbits utilize different forage sources depending on the vegetation types.Conclusions:Rabbits regularly inhabit the forest,even though it is not their preferred vegetation type to live.Rabbit management entails isolating regions that are more favourable to intake and emphasizing the year’s season for rabbit control efforts.
基金partially financed by PICT 2016-0586(Agencia Nacional de Promocion de la Investigacion,el Desarrollo Tecnologico y la Innovacion)INTA PD096 from(Instituto Nacional de Tecnología Agropecuaria),Argentina.
文摘Management under ecological schemes and increasing habitat heterogeneity,are essential for enhancing biodiversity in vineyards.Birds provide several contributions to agriculture,for example pest control,recreation and enhancing human mental health,and have intrinsic value.Birds are also ideal model organisms because they are easy to survey,and species respond differently to agricultural land use at different scales.Vegetated borders of crops are key for many species of birds,and distance to the border have been found to be an important factor in vineyard-dominated agroecosystems.We evaluate if there are differences in the bird assemblage,between the interior compared to borders within vineyards,using a hierarchical community occupancy model.We hypoth-esized that occupancy of birds is greater in environments with greater heterogeneity,which in this study was considered to be contributed by the proximity to vegetated corridors.We expected that vineyard borders close to corridors will have higher bird occupancy than the center of the vineyard.The research was conducted in three vineyards with biodiversity-friendly management practices,in Gualtallary,Mendoza,Argentina.Bird surveys were conducted over three breeding seasons from 2018 to 2020.Occupancy and richness of the bird community was more closely associated with the borders adjacent to the corridors than with the interior of the vineyards,as we initially predicted,although the assemblage of birds did not differ much.More than 75%of the registered species consume exclusively or partially invertebrates.Biodiversity-friendly management and ecological schemes,together with vegetated corridors provide multiple benefits for biodiversity conservation.These ap-proaches not only minimize the use of agrochemicals but also prioritize soil cover with spontaneous vegetation,which supports a diverse community of insectivorous bird species,potentially contributing to pest control.
基金Resources for this study were obtained from INTA Projects.
文摘Semiarid Patagonia represents 25%of the rangeland area in Argentina,and sheep overgrazing has degraded about a third of it in the past.In this century,depleted domestic stocks have mostly stabilized,but Guanaco populations have grown.These native camelids share habitat and diets with sheep,but their effect on vegetation is poorly understood and has long been debated.We set up an exclusion experiment in Monte León and Cañadón Vaca,a semiarid shrubland grassland in southern Patagonia,currently grazed only by guanacos.Vegetation baselines were studied in 2016 in twelve plots,and half of them were protected from guanaco grazing.Thirty-six plots were cleared to study revegetation.Vegetation was reassessed in 2021,and changes were evaluated using a paired t-test.Within protected plots,vegetation cover increased,bare soil diminished,and vegetated patches grew in size,but the density of the patch-interpatch arrangement did not change.Biodiversity,measured by richness and the Shan-non-Wiener(SW)index,grew significantly.Nutrient recycling increased,as did the Stability and Infiltration Land Function indexes,although these last differences were not significant.Vegetation cover under guanaco grazing also increased,mainly due to the growth of dwarf shrubs,a typical tendency in sheep grazing-induced transitions in the region.Vegetated patches under grazing fragmented,resulting in smaller patches and denser patch struc-tures,while diversity and land function indexes remained unchanged.Young plants established in cleared plots without guanacos showed higher cover density and individual size.These effects are similar to those observed in numerous experimental sheep exclosures.Guanaco grazing may thus prevent restoration and contribute to the generalized land degradation processes that overgrazing has been causing in Patagonia for over a century.
基金supported by FONDECYT Initiation in Research,grant number 11201141,awarded to PJU.
文摘Ferroptosis,an iron-dependent cell death:Ferroptosis is a type of regulated necrosis,characterized by redox-active iron accumulation and increased free radical production derived by Fenton chemistry,that triggers oxidation of polyunsaturated fatty acids in phospholipids,loss of cellular membranes integrity,and leakage of intracellular contents.
基金supported by Facultad de Ciencias Exactas y Naturales de la Universidad Nacional de La Pampa(FCEyN-UNLPam).
文摘Beneficial microbes can improve soil health by promoting soil structure,nutrient cycling,and disease suppression.In addition,a wide array of rhizospheric microbes are responsible for producing metabolically active compounds including various types of plant growth regulators.So,microbial biodiversity studies could contribute to the improvement of agricultural practices in deprived areas,such as the Pampean semiarid region.The vast majority of studies conducted on endophytic microorganisms have focused on intensive crop legume species.In contrast,little attention has been paid to microorganisms of native legumes,whose ecology is not directly affected by human action.In this study,endophytic microorganisms isolated from root nodules of a selected native legume of the genus Rhynchosia were characterized.Viable isolates were studied with a focus on their plant growth-pro-moting rhizobacteria(PGPR)properties.Considering the edaphic characteristics of the Pampean semiarid region,the isolates obtained were evaluated for their ability to grow under three salt stress conditions(50,100,and 200 mM NaCl)and four different pH values(6,7,8,and 9).Based on their PGPR activities,the selected strains were phylogenetically grouped using BOX-PCR.The results showed great variability among the isolates in terms of the characteristics studied.Native legumes manifested a wide endophytic variability and remarkable perfor-mance in PGPR activities.We conclude that they could be used as potential bioinoculants for legume cultivation,an excellent alternative to the use of chemical fertilizers that currently pollute the environment.
文摘This experiment aimed to evaluate the effect of calcium salts of linseed oil (rich in alpha-linolenic acid (ALA, C18:3n-3) on metabolic and reproductive traits in high-producing dairy cows under grazing. Thirty-six Holstein dairy cows were randomly assigned, in a complete block design, to receive ALA supplementation (0.85 kg∙day−1 of calcium salts of linseed oil) or to remain as untreated control (CON). The concentrate was formulated to offer the same amount of energy across treatments (CON cows received an extra kg of corn to compensate for the higher energy density of ALA treatment). A PMR + Alfalfa pasture was offered to all cows at the same time. A fixed time artificial insemination (FTAI) at 80 DIM, preceded by a Presynch plus Ovsynch protocol was implemented for the first service and later, on return to estrus, heat detection and artificial insemination (AI) were performed. Pregnancy diagnosis was checked at 30, 42, 60, and 90 d after AI. Blood and milk samples were taken biweekly. Treatment affected plasma cholesterol concentration (160.36 vs. 186.70 mg∙dl−1, p = 0.03, for ALA and CON, respectively) and on size of corpus luteum (CL, 17.6 vs. 13.7 mm, p = 0.02, for ALA and CON, respectively). Supplementation tended (p = 0.136) to increase conception rate by 200 DIM (81.69% vs. 55.43% in ALA and CON cows, respectively). However, treatment had no effect (p > 0.05) on body weight (BW), body condition score (BCS), and circulating levels of beta-hydroxybutyrate (BHBA), glucose, insulin, growth hormone (GH) and insulin-like growth factor (IGF-I). Our results suggest that supplementation with calcium salts of linseed oil could enhance ovarian function without affecting energy metabolism in early lactation dairy cows.
文摘The Puna grasslands support grazing systems that produce meat and wool in multi-species herds,especially from llama(Lama glama)and sheep.However,it is yet unknown whether grazing pressure can modify grassland structure and Plant Functional Types diversity and cover in Puna grasslands.We analyzed the relationship between grazing pressure and Plant Functional Types by comparing transects located near stockyards(high grazing pressure)and far from them(low pressure)and by evaluating the relationship between the Plant Functional Types cover to a Grazing Pressure Index(GPI).This index incorporates the heterogeneity of traditional pastoral management.At two ecological sites(Ciénego and Tolar),we sampled paired transects(near-far).Plots near and far from corrals were similar in all the variables measured except for plots in Tolar,which tend to have higher total cover,possibly due to fecal fertilization near stockyards.Furthermore,we recorded an increase in total cover and grass cover at higher GPI in Ciénego,while in Tolar we found lower values of total cover and herbaceous dicotyledonous cover at intermediate intensities of GPI.The only negative relationship found was the cover of clonal and non-clonal shrubs,possibly explained by the greater use of these shrubs as firewood near stockyards.In summary,our study does not show important changes in Plant Functional Types as a function of grazing pressure in the studied grasslands probably because grazing pressure is diluted or diminished when livestock rotates in different areas and grazing durations vary.Finally,the long grazing history with which the Puna has evolved could also contribute to the co-structuration between native vegetation and livestock farming.
文摘Anaerobic digestion is a process that is widely used for the treatment of organic wastes. The digestate can be used as a soil amendment or crop fertiliser. The aims of our work were to evaluate 1) the physicochemical composition and pathogen content in a digestate from poultry manure, according to international regulations, and 2) the effect of its soil application on the major chemical and biological soil properties and on the growth of Lactuca sativa. The experiment consisted of two groups of pots(with and without crop). Treatments applied to each group were as follows: low and high doses of digestate and inorganic fertiliser, and no application(control)(low dose: 70 kg nitrogen(N) ha^(-1) and 21 kg phosphorus(P) ha^(-1); high dose: 210 kg N ha^(-1) and 63 kg P ha^(-1)). Soil samples were taken 7 and 34 d(harvest) after treatment applications. Heavy metal and pathogen contents in the digestate were below the upper limit values. Despite the high pH and electrical conductivity values of the digestate, both soil parameters presented acceptable values for crop growth. Although there were no initial increases in total inorganic N and available P in soil with digestate application, an increase in the fresh weight of crop was observed with the high dose application. This is probably associated with the slow nutrient release from the digestate during the development of the crop. Changes in the microbial community were temporary and occurred at the initial sampling stage of the experiment.
文摘Rapid emergence and a vigorous growth prevent the seed tubers from infections by soil microbes and allow a rapid interception of solar radiation. In this work, the effect of the potassium phosphites (KPhi) applied to seed tubers of two potato cultivars on crop emergence and early growth was studied. Two experiments were performed under greenhouse and field conditions. Emergence of plants, leaf area, dry matter and the number of primary stems were measured in both experiments. Furthermore, mycorrhizal colonization was also measured on roots under field conditions. The application of KPhi reduced the period between planting and emergence, and increased leaf area and dry matter. The ratio between dry matter of aerials and underground organs was not affected by KPhi. Indigenous mycorrhizal colonization increased after KPhi application to seed tubers. These results confirm the benefit of the application of KPhi to seed tubers on early plant growth and suggest that their application in crop production would be advantageous.
文摘Forty multiparous Holstein cows in early lactation (66 ± 19 days) were assigned to one of four treatments that consisted in different ratios of total mixed rations (TMR) and pasture at 100% TMR (T0), 75:25 (T1) 50:50 (T2) and 25:75 (T3) over 9 weeks in autumn-winter. Measures of rumen parameters and digestion were performed on 4 additional Holstein cows in late lactation (287 days postpartum) fitted with permanent ruminal fistulae and producing 22.6 (±5.4) kg milk in a 4 × 4 Latin Square design. In T1 to T3 cows were taken to the grazing plot once they finished the pre-planned TMR intake and pasture was offered at 2 times the expected forage DM intake. Milk was analyzed for chemical composition, milk fatty acid (FA) profile and antioxidant compounds. The cows were individually weighed and body condition score (BCS) was determined. After the morning milking, blood samples were taken every 2 weeks and plasma was analyzed for glucose, urea, non-esterified fatty acids (NEFA), insulin, growth hormone (GH) and insulin-like growth factor (IGF-I). Herbage mass in pre grazing strips of pasture averaged 2540 ± 343 kg DM/ha. As TMR intake increased, production variables increased linearly excepting milk fat (3.88 g/100g) and milk protein (3.43 g/100g) contents that were not affected. Milk yield (kg/cow/d) resulted maximal in T0 (34.2) and linearly decreased (p 3-N concentration resulted higher in treatments with higher proportion of pasture. Kinetic parameters of DM and NDF digestion from pasture or corn silage were not affected. Milk FA profile and milk antioxidant quality showed unfavorably changes as TMR increased by a decrease in rumenic and linolenic acids and content of antioxidant vitamins, without effect on the atherogenicity index. Results suggested a depressing effect of the pasture on total DM and energy intake probably explained by qualitative deficiencies chemical composition of the forage and/or factors that affect animal behavior that may induce losses in body condition of high yielding dairy cows.
文摘Rapid and sensitive reversed phase high performance liquid chromatography (RP-HPLC) and ultra performance liquid chromatography (RP-UPLC) method with UV detection has been developed and validated for quantification of parathyroid hormone (PTH) in presence of meta-cresol as a stabilizer in a pharmaceutical formulation.Chromatography was performed with mobile phase containing 0.1% Trifluoroacetic acid (TFA) in MilliQ water and 0.1% TFA in acetonitrile with gradient program and flow rate at 0.3 mL/min for HPLC and 0.4 mL/min for UPLC.Quantification was accomplished with internal reference standard (qualified against innovator product and National Institute for Biological Standards and Control (NIBSC) standard).The methods were validated for linearity (correlation coefficient 0.99),range,accuracy,precision and robustness.Robustness was confirmed by considering three factors;mobile phase composition,column temperature and flow rate/age of mobile phase.Intermediate precision was confirmed on different equipments,different columns and on different days.The relative standard deviation (RSD) (<2% for RP-HPLC and <1% for UPLC,n=30) indicated a good precision.Retention time was found about 17 min and 2 min by HPLC and UPLC methods,respectively.Both methods are simple,highly sensitive,precise and accurate and have the potential of being useful for routine quality control.
文摘This paper describes a method for mesh adaptation in the presence of intersections, such as wing-fuselage. Automatic optimization tools, using Computational Fluid Dynamics（CFD） simulations, face the problem to adapt the computational grid upon deformations of the boundary surface. When mesh regeneration is not feasible, due to the high cost to build up the computational grid, mesh deformation techniques are considered a cheap approach to adapt the mesh to changes on the geometry. Mesh adaptation is a well-known subject in the literature; however, there is very little work which deals with moving intersections. Without a proper treatment of the intersections,the use of automatic optimization methods for aircraft design is limited to individual components.The proposed method takes advantage of the CAD description, which usually comes in the form of Non-Uniform Rational B-Splines（NURBS） patches. This paper describes an algorithm to recalculate the intersection line between two parametric surfaces. Then, the surface mesh is adapted to the moving intersection in parametric coordinates. Finally, the deformation is propagated through the volumetric mesh. The proposed method is tested with the DLR F6 wing-body configuration.
基金supported by the Instituto Nacional de Tecnologa Agropecuaria of Argentina(INTA PNSUELO 1134044)the Fondo Para la Investigacion Cientfica y Tecnologica of Argentina(PICT 448)
文摘Glyphosate is the most used herbicide in Argentina, accounting for 62% of the commercialized pesticides on the market. It is used as a weed controller in no-till systems, and it is also applied to various genetically modified crops ( e.g., soybean, corn, and cotton). Although it has a high solubility in water, it tends to adsorb and accumulate in agricultural soils. The main objectives of this work were to compare the dissipation of glyphosate and the accumulation of its metabolite aminomethylphosphonic acid (AMPA) over time in three soils from agricultural areas of Argentina under long-term management with no-till (NT) and conventional tillage (CT) practices. There were no differences in dissipation between NT and CT, indicating that the glyphosate-degrading microflora was not modified by the different tillage managements. Moreover, tillage practices did not alter the general soil properties;therefore, glyphosate bioavailability was not affected by NT or CT practice. Forty percent of the applied glyphosate was degraded within the first three days in all soils, indicating a fast initial dissipation rate. However, the dissipation rate considerably decreased over time, and the degradation kinetics followed a bi-exponential (or two-compartment) kinetic model. No differences were found between tillage practices. Dissipation was not related to the microbial activity measured as soil respiration. The fast decrease in the concentration of glyphosate at the beginning of the dissipation study was not reflected in an increase in the concentration of AMPA. The estimated half-lives for glyphosate ranged between 9 and 38 d. However, glyphosate bioavailability decreases over time, as it is strongly adsorbed to the soil matrix. This increases its residence time, which may lead to its accumulation in agricultural soils.
文摘The aim of the study was to determine the effect of three levels of energy concentrate intake on dry matter (DM) and energy intake, milk yield and composition, rumen environment and pasture neutral detergent fiber (NDF) digestion. Twelve Holstein multiparous cows in early lactation (69.0 ± 5 days postpartum) producing 32.8 (±4.0) kg milk were assigned to three treatments at (kg/cow day) 3.5 (T3.5), 7.0 (T7.0) and 10.5 (T10.5) kg concentrate in a 3 × 3 Latin Square design. Parameters of ruminal environment and neutral detergent fiber (NDF) digestion were obtained using 3 additional rumen cannulated cows. Concentrate was composed (as fed) by corn grain (68%), soybean meal (22%), wheat bran (8%) and a vitamin-mineral premix including monensin and thoroughly consumed. Yields (kg/cow day-1) of milk, 4% fat corrected milk (4% FCM 4%) and energy corrected milk (ECM) resulted higher (p p -1 without effects on yield of milk fat. Concentrations (g/100 g) of milk fat (3.19), protein (2.97), total solids (11.75), non-fat solids (8.60) and casein (2.40) did not differ. Milk lactose content (g/100 g) was linearly increased (p p p p p < 0.05) in T3.5 due to the increase in acetate and butyrate while the acetate: Propionate ratio remained unchanged. Pasture NDF digestion was affected as concentrate intake increased. To increase milk protein yield and reduce concentrations of N-NH3 in rumen and milk, feeding an energy concentrate at 41% of total DM intake resulted an effective tool.
基金supported by grants AERG 232141/PNBIO 1131032 from the Instituto Nacional de Tecnología Agropecuaria(INTA)PICT 2008-0400 from the Agencia Nacional de Promoción Científica y Tecnológica(ANPCyT),Argentina
文摘Dear Editor,Infectious bursal disease virus（IBDV）causes infectious bursal disease,a highly contagious immunosuppressive disease that affects young chickens and causes economic losses in the poultry industry worldwide.IBDV replicates mainly in actively dividing B lymphocytes within the bursa of Fabricius（BF）,leading to immunosuppression in affected flocks（Mahgoub et al.,2012）.Viral protein 2（VP2）,
文摘The objective was to reduce saturated fatty acids (SFA) and increase conjugated linoleic acid (CLA, cis-9, trans-11 C18:2), α-linolenic (cis-9, cis-12, cis-15 C18:3) and docosahexaenoic (DHA, C22:6) contents in milk from confined dairy cows in order to promote a healthier option. The work was carried out in a commercial farm (Talar) located in Laguna del Sauce, Maldonado (Uruguay). Twenty four cows were assigned to one of two treatments (12 cows per treatment) over a 6 weeks experimental period. Treatments consisted in a control total mixed ration (C-TMR) without supplementary lipids (L) or the same TMR with the addition of 0.144 kg/cow·day of algae and 0.72 kg/cow·day of soybean oil (L-TMR). Chemical composition of the TMR (44.27% DM) averaged 15.94% for crude protein (CP), 38.20% neutral detergent fiber (NDF), 20.36% acid detergent fiber (ADF), 5.56% fat, 5.30% ash and 28.6% nonstructural carbohydrate (NSCH) with 1.81 Mcal/kg of net energy for lactation (NEL). After 39 days of feeding, individual milk samples were collected during three consecutive days. From the total milk collected, 20 ml were immediately used for chemical composition (Milko Scan) and 80 ml for analysis for milk FA profile. From week 3 onwards, milk production (kg/cow·day) resulted higher (P P P = 0.43) on milk protein content (C-TMR = 3.20;L-TMR = 3.07 g/100g). Milk lactose (C-TMR = 4.86, L-TMR = 4.69 g/100g) and urea nitrogen contents (C-TMR = 21.18, L-TMR = 17.33 g/100g) tended (P cow·day, P 12:0 to C16:0 FA averaging 45.19 in C-TMR and 34.74 g/100g in L-TMR (P P 18:1 trans-9) (0.23) and C18:1 trans-10 (0.44) FA increased (P trans-11 C18:1, VA) increased from 1.08 in C-TMR to 2.56 g/100g of FA in L-TMR (P cis-9, trans-11 C18:2) increased (127%) from 0.62 in C-TMR to 1.41 g/100g FA in L-TMR milk. Content of α-linolenic acid resulted 20% higher (P P cis-9 C18:1) resulted higher (P α-linolenic).
文摘The Gulf of Cadiz is situated geologically at the Gibraltar Arc, the westernmost arc of the Alpine- Himalayan orogenic belt. Based on extensive previous studies that include swath bathymetry, multi-channel and very high-resolution seismic reflection, gravime- try, magnetism, heat flow probes, and underwater photography surveys, more than 500 polymetallic nodules were collected at water depths ranging from 850 to 1000 m, associated with hydrocarbon-derived carbonate chimneys, slabs, and crusts. Nodules show a wide range of sizes, densities, weights and mor- phologies. Nodules are composed of multiple milli- metre-thick layers of Fe and Mn oxyhydroxides sur- rounding a nucleus composed of Early-Middle Mio- cene plastic marls, which were expulsed from underly- ing units by fluid venting. Nodules show a high mean abundance of Fe （39.03%）, moderate Mn （5.84%）,
文摘Increased levels of stress hormones in the muscle could lead to post mortem metabolic/structural modiifcations that could be relfected on meat quality. The present study investigated the metabolic effect of either adrenaline or cortisol injected into lambs in order to obtain an animal model of acute stress. Results showed that adrenaline or cortisol injection lead to glucose metabolism and muscle temperature increase. Muscle pH immediately post mortem was affected by adrenaline treatment. Water holding capacity （WHC） of fresh muscle, ifnal muscle pH and temperature registered at 24 h post mortem were not affected by injected hormones. Hardness and adhesiveness of LD muscle evaluated 3 d post mortem tended to increase as a result of adrenaline or cortisol injection. Results demonstrated that injected hormones were able to affect the post mortem muscle biochemistry and the pH/T curve independently of ifnal muscle pH.
