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1.
GM Crops Food ; 12(1): 71-83, 2021 Jan 02.
Artigo em Inglês | MEDLINE | ID: mdl-32997586

RESUMO

This study assessed the farm-level economic and environmental impacts from the use of genetically modified (GM) corn in Vietnam (resistant to Lepidopteran pests of corn and tolerant to the herbicide glyphosate). It was largely based on a farmer survey conducted in 2018-19. The GM varieties out-performed conventional varieties in terms of yield by +30.4% (+15.2% if the yield comparison is with only the nearest performing equivalent conventional varieties) and reduced the cost of production by between US $26.47 per ha and US $31.30 per ha. For every extra US $1 spent on GM seed relative to conventional seed, farmers gained between an additional US $6.84 and US $12.55 in extra income. The GM maize technology also reduced insecticide and herbicide use. The average amount of herbicide active ingredient applied to the GM crop area was 26% lower (1.66 kg per ha) than the average value for the conventional corn area (2.26 kg/ai per ha) and in terms of the associated environmental impact of the herbicide use, as measured by the Environmental Impact Quotient (EIQ) indicator, it was lower by 36% than the average value applicable to the conventional corn area. Insecticides were used on a significantly lower GM crop area and, when used, in smaller amounts. The average amount of insecticide applied to the GM corn crop was significantly lower by 78% (0.08 kg/ai per ha) than the average value for the conventional corn area (0.36 kg/ai per ha) and in terms of the associated environmental impact of the insecticide use, as measured by the EIQ indicator, it was also lower by 77% than the average value for conventional corn (14.06 per ha).


Assuntos
Produtos Agrícolas/genética , Zea mays/genética , Fazendas , Plantas Geneticamente Modificadas/genética , Inquéritos e Questionários , Vietnã
2.
Nat Commun ; 11(1): 4954, 2020 10 02.
Artigo em Inglês | MEDLINE | ID: mdl-33009396

RESUMO

Genetic variation is of crucial importance for crop improvement. Landraces are valuable sources of diversity, but for quantitative traits efficient strategies for their targeted utilization are lacking. Here, we map haplotype-trait associations at high resolution in ~1000 doubled-haploid lines derived from three maize landraces to make their native diversity for early development traits accessible for elite germplasm improvement. A comparative genomic analysis of the discovered haplotypes in the landrace-derived lines and a panel of 65 breeding lines, both genotyped with 600k SNPs, points to untapped beneficial variation for target traits in the landraces. The superior phenotypic performance of lines carrying favorable landrace haplotypes as compared to breeding lines with alternative haplotypes confirms these findings. Stability of haplotype effects across populations and environments as well as their limited effects on undesired traits indicate that our strategy has high potential for harnessing beneficial haplotype variation for quantitative traits from genetic resources.


Assuntos
Haplótipos/genética , Característica Quantitativa Herdável , Zea mays/genética , Biblioteca Gênica , Variação Genética , Genoma de Planta , Estudo de Associação Genômica Ampla , Haploidia , Melhoramento Vegetal , Análise de Componente Principal , Zea mays/crescimento & desenvolvimento
3.
J Environ Qual ; 49(1): 220-227, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33016352

RESUMO

The economic viability of corn biorefineries depends heavily on the sale of coproducts as animal feeds, but elevated phosphorus (P) contents can exacerbate manure management issues. Phosphorus removal from light steep water and thin stillage, two concentrated in-process aqueous streams at wet milling and dry-grind corn biorefineries, could simultaneously generate concentrated fertilizer and low-P animal feeds, but little is known regarding how differences in stream composition affect removal. To address this data gap, we show that the solubility of P in light steep filtrate (LSF) and thin stillage filtrate (TSF) exhibits distinct sensitivity to calcium (Ca) and base addition due to differences in P fractionation and protein abundance. In LSF, P was primarily organic, and near-complete removal of P (96%) was observed at pH 8 and a Ca/total P (TP) ratio of 2. In TSF, TP removal was lower (81%), and there was more equal distribution of organic and orthophosphate, indicating that the Ca requirements of inorganic P precipitation were a limiting factor. The C/H/N ratio, elemental characterization, and crude protein analysis of the precipitated solids indicated that coprecipitation of amorphous solids containing Ca, Mg, and K with soluble proteins facilitated removal of P, particularly in LSF. Although the removal mechanisms and solubility limits differed, these results highlighted the magnitude (40-70 mM) and efficacy (80-96%) of P recovery from two biorefinery streams.


Assuntos
Fósforo , Zea mays , Ração Animal , Animais , Fracionamento Químico , Água
4.
J Environ Qual ; 49(1): 38-49, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33016359

RESUMO

Grain producers are challenged to maximize crop production while utilizing nutrients efficiently and minimizing negative impacts on water quality. There is a particular concern about nutrient export to the Gulf of Mexico via loss from subsurface drainage systems. The objective of this study was to investigate the effects of crop rotation, tillage, crop residue removal, swine manure applications, and cereal rye (Secale cereale L.) cover crops on nitrate-N (NO3 -N) and total reactive phosphorus (TRP) loss via subsurface drainage. The study was evaluated from 2008 through 2015 using 36 0.4-ha plots outfitted with a subsurface drainage water quality monitoring system. Results showed that when swine manure was applied before both corn (Zea mays L.) and soybean [Glycine max (L.) Merr.], drainage water had significantly higher 8-yr-average flow-weighted NO3 -N concentrations compared with swine manure applied before corn only in a corn-soybean rotation. The lowest NO3 -N loss was 15.2 kg N ha-1  yr-1 from a no-till corn-soybean treatment with rye cover crop and spring application of urea-ammonium nitrate (UAN) to corn. The highest NO3 -N loss was 29.5 kg N ha-1  yr-1 from swine manure applied to both corn and soybean. A rye cover crop reduced NO3 -N loss, whereas tillage and residue management had little impact on NO3 -N loss. Losses of TRP averaged <32 g P ha-1  yr-1 from all treatments. Corn yield was negatively affected by both no-till management and cereal rye cover crops. Results showed that cropping management affected N leaching but impacts on P leaching were minimal.


Assuntos
Agricultura , Qualidade da Água , Animais , Nitrogênio/análise , Soja , Suínos , Zea mays
5.
J Environ Qual ; 49(3): 628-639, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-33016385

RESUMO

An integrated crop-livestock system (ICLS), when managed properly, can help in mitigating soil surface greenhouse gas (GHG) fluxes, especially carbon dioxide (CO2 ), methane (CH4 ), and nitrous oxide (N2 O). However, the impacts of an ICLS on GHG fluxes are poorly understood. The present study was conducted at two sites (northern Brookings [Brookings-N] and northwestern Brookings [Brookings-NW]) established in 2016 and 2017, respectively, under loamy soils in South Dakota. The specific objective was to evaluate the impact of cover crops (CCs) and grazed CCs under oat (Avena sativa L.)-CCs-maize (Zea mays L.) rotation on GHG fluxes. Study treatments included the following: (a) a legume-dominated CC (LdC), (b) a cattle-grazed LdC (LdC+G), (c) a grass-dominated CC (GdC), (d) a cattle-grazed GdC (GdC+G), and (e) one without CC or grazing (NC). Greenhouse gas monitoring occurred weekly during the growing crop seasons in 2016 and 2017 for Brookings-N and in 2017 and 2018 for Brookings-NW. Data showed that cumulative CO2 and N2 O fluxes at Brookings-N were lower for GdC+G (4042 kg C ha-1 for CO2 and 1499 g N ha-1 for N2 O) than for LdC+G (4819 kg C ha-1 for CO2 and 2017 g N ha-1 for N2 O), indicating the superiority of GdC+G over LdC+G in reducing GHG fluxes. However, no effect from grazed CC on cumulative CO2 and N2 O fluxes were observed at the Brookings-NW site. Cumulative CH4 flux was not affected by an ICLS at either site. This short-term investigation showed that, in general, CCs and grazing of CCs and maize residue did not impact GHG fluxes.


Assuntos
Gases de Efeito Estufa , Animais , Bovinos , Produtos Agrícolas , Óxido Nitroso/análise , Solo , Zea mays
6.
J Environ Qual ; 49(3): 745-753, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-33016408

RESUMO

Manure is commonly used as a fertilizer or soil conditioner; however, land application of untreated manure may introduce pathogens and antibiotic-resistant bacteria (ARB) into the soil, with harmful implications for public health. Composting is a manure management practice wherein a carbon-rich bulking agent, such as corn (Zea mays L.) stalk residue, is added to manure to achieve desirable carbon/nitrogen ratios to facilitate microbial activities and generate enough heat to inactivate pathogens, including antibiotic-resistant pathogens. However, when comparing compost piles and stockpiles for ARB reduction, we noticed that bulking agents added ARB to composting piles and compromised the performance of composting in reducing ARB. We hypothesized that ARB could be prevalent in corn stalk residues, a commonly used bulking agent for composting. To test this hypothesis, corn stalk residue samples throughout Nebraska were surveyed for the presence of ARB. Of the samples tested, 54% were positive for antibiotic-resistant Escherichia coli or enterococci using direct plating or after enrichment. Although not statistically significant, there was a trend wherein the use of pesticides tended to result in a greater prevalence of some ARB. Results from this study suggest that bulking agents can be a source of ARB in manure composting piles and highlight the importance of screening bulking agents for effective ARB reduction in livestock manure during composting.


Assuntos
Compostagem , Antibacterianos , Bactérias , Esterco , Nebraska , Zea mays
7.
J Environ Qual ; 49(5): 1298-1309, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-33016457

RESUMO

Tillage incorporation of manure can mitigate nutrient loss but increases erosion potential and damages cover crops. More information on the effects of low-disturbance manure application (LDMA) on corn yield, cover crop establishment, and soil properties is needed to better predict manure management practice trade-offs. Here, corn silage (Zea mays L.) yield, winter rye (Secale cereale L.) establishment, and soil nitrate concentrations were compared for a range of manure application methods, including broadcast incorporation, broadcast/disk, fertilizer N (spring applied at 67, 134, and 202 kg N ha-1 ), and a no-manure control, at the University of Wisconsin's Marshfield Agricultural Research Station from 2012 to 2015. Compared with the control, manure and fertilizer N treatments increased corn yield by an average of 1.1- to 1.6-fold and 1.4- to 1.6-fold, respectively. Of the LDMA treatments (sweep-, strip till-, and coulter-injection; aerator/band; broadcast), corn yield was greatest for sweep injection, which did not differ from the high N fertilizer rate (P < .0001). Corn yield averaged across LDMA treatments did not differ from the 134 or 202 kg N ha-1 yields. Compared with disking, LDMA maintained more crop residue (P < .0001), with levels comparable to the control. Soil nitrate-N at depths of 0-30 and 30-60 cm was influenced by LDMA and fertilizer N; however, leaching to 60-90 cm was comparable among treatments. Results indicate that LDMA with injection conserved more N, caused less damage to winter rye, and had similar yields to fertilizer N treatments with improved soil aggregate stability and higher total carbon content.


Assuntos
Silagem , Zea mays , Esterco , Secale , Solo
8.
J Environ Qual ; 49(5): 1236-1250, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-33016461

RESUMO

A critical question is whether there are agricultural management practices that can attain the multiple management goals of increasing yields, preventing nutrient losses, and suppressing greenhouse gas (GHG) emissions. No-till and manure application methods, such as manure injection, can enhance nutrient retention, but both may also enhance emissions of nitrous oxide (N2 O), a powerful GHG. We assessed differences in soil N2 O and carbon dioxide (CO2 ) emissions, nitrate and ammonium retention, and crop yield and protein content under combinations of vertical-till, no-till, manure injection, and manure broadcast without incorporation in a corn (Zea mays L.) silage system. During the growing seasons of 2015-2017, GHG emissions and soil mineral nitrogen (N) were measured every other week or more frequently after management events. Crop yield and protein content were measured annually at harvest. No-till reduced CO2 emissions but had no impact on N2 O emissions relative to vertical-till. Manure injection increased N2 O and CO2 emissions, with the magnitude of this effect being greatest for 1 mo post-application. Manure injection also increased soil ammonium and nitrate but did not increase yield or crop quality relative to broadcast application. Similarly, tillage did not affect crop yield or protein content. Despite the tradeoffs between mineral N retention and elevated GHG emissions, manure injection in no-till systems benefits farmers by reducing soil carbon losses as CO2 , retaining mineral N, and maintaining crop yields and quality.


Assuntos
Esterco , Silagem , Óxido Nitroso/análise , Solo , Zea mays
9.
J Environ Qual ; 49(4): 882-895, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-33016498

RESUMO

Farmers, food supply companies, and policymakers need practical yet scientifically robust methods to quantify how improved nitrogen (N) fertilizer management can reduce nitrous oxide (N2 O) emissions. To meet this need, we developed an empirical model based on published field data for predicting N2 O emission from rainfed maize (Zea mays L.) fields managed with inorganic N fertilizer in the United States and Canada. Nitrous oxide emissions ranged widely on an area basis (0.03-32.9 kg N ha-1 yr-1 ) and a yield-scaled basis (0.006-4.8 kg N Mg-1 grain yr-1 ). We evaluated multiple modeling approaches and variables using three metrics of model fit (Akaike information criteria corrected for small sample sizes [AICc], RMSE, and R2 ). Our model explains 32.8% of the total observed variation and 50% of observed site-level variation. Soil clay content was very important for predicting N2 O emission and predicting the change in N2 O emission due to a change in N balance, with the addition of a clay fixed effect explaining 37% of site-level variation. Sites with higher clay content showed greater reductions in N2 O emission for a given reduction in N balance. Therefore, high-clay sites are particularly important targets for reducing N2 O emissions. Our linear mixed model is more suitable for predicting the effect of improved N management on N2 O emission in maize fields than other published models because it (a) requires only input data readily available on working farms, (b) is derived from field observations, (c) correctly represents differences among sites using a mixed modeling approach, and (d) includes soil texture because it strongly influences N2 O emissions.


Assuntos
Gases de Efeito Estufa , Zea mays , Agricultura , Canadá , Nitrogênio , Estados Unidos
10.
Plant Genome ; 13(1): e20008, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-33016632

RESUMO

Sweet corn (Zea mays L.) is highly consumed in the United States, but does not make major contributions to the daily intake of carotenoids (provitamin A carotenoids, lutein and zeaxanthin) that would help in the prevention of health complications. A genome-wide association study of seven kernel carotenoids and twelve derivative traits was conducted in a sweet corn inbred line association panel ranging from light to dark yellow in endosperm color to elucidate the genetic basis of carotenoid levels in fresh kernels. In agreement with earlier studies of maize kernels at maturity, we detected an association of ß-carotene hydroxylase (crtRB1) with ß-carotene concentration and lycopene epsilon cyclase (lcyE) with the ratio of flux between the α- and ß-carotene branches in the carotenoid biosynthetic pathway. Additionally, we found that 5% or less of the evaluated inbred lines possessing the shrunken2 (sh2) endosperm mutation had the most favorable lycE allele or crtRB1 haplotype for elevating ß-branch carotenoids (ß-carotene and zeaxanthin) or ß-carotene, respectively. Genomic prediction models with genome-wide markers obtained moderately high predictive abilities for the carotenoid traits, especially lutein, and outperformed models with less markers that targeted candidate genes implicated in the synthesis, retention, and/or genetic control of kernel carotenoids. Taken together, our results constitute an important step toward increasing carotenoids in fresh sweet corn kernels.


Assuntos
Carotenoides , Zea mays , Estudo de Associação Genômica Ampla , Fenótipo , Zea mays/genética , beta Caroteno
11.
Plant Genome ; 13(1): e20003, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-33016634

RESUMO

Root anatomical phenes have important roles in soil resource capture and plant performance; however, their phenotypic plasticity and genetic architecture is poorly understood. We hypothesized that (a) the responses of root anatomical phenes to water deficit (stress plasticity) and different environmental conditions (environmental plasticity) are genetically controlled and (b) stress and environmental plasticity are associated with different genetic loci than those controlling the expression of phenes under water-stress and well-watered conditions. Root anatomy was phenotyped in a large maize (Zea mays L.) association panel in the field with and without water deficit stress in Arizona and without water deficit stress in South Africa. Anatomical phenes displayed stress and environmental plasticity; many phenotypic responses to water deficit were adaptive, and the magnitude of response varied by genotype. We identified 57 candidate genes associated with stress and environmental plasticity and 64 candidate genes associated with phenes under well-watered and water-stress conditions in Arizona and under well-watered conditions in South Africa. Four candidate genes co-localized between plasticity groups or for phenes expressed under each condition. The genetic architecture of phenotypic plasticity is highly quantitative, and many distinct genes control plasticity in response to water deficit and different environments, which poses a challenge for breeding programs.


Assuntos
Raízes de Plantas , Zea mays , Regulação da Expressão Gênica , Raízes de Plantas/genética , Solo , Água , Zea mays/genética
12.
Plant Genome ; 13(1): e20014, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-33016635

RESUMO

Genomic prediction (GP) might be an efficient way to improve haploid induction rate (HIR) and to reduce the laborious and time-consuming task of phenotypic selection for HIR in maize (Zea mays L.). In this study, we evaluated GP accuracies for HIR and other agronomic traits of importance to inducers by independent and cross-validation. We propose the use of GP for cross prediction and parental selection in the development of new inducer breeding populations. A panel of 159 inducers from Iowa State University (ISU set) was genotyped and phenotyped for HIR and several agronomic traits. The data of an independent set of 53 inducers evaluated by the University of Hohenheim (UOH set) was used for independent validation. The HIR ranged from 0.61 to 20.74% and exhibited high heritability (0.90). High cross-validation prediction accuracy was observed for HIR (r = 0.82), whereas for other traits it ranged from 0.36 (self-induction rate) to 0.74 (days to anthesis). Prediction accuracies across different sets were higher when the larger panel (ISU set) was used as a training population (r = 0.54). The average HIR of the 12,561 superior predicted progenies (µSP ) ranged from 1.00-18.36% and was closely related to the corresponding midparent genomic estimated breeding value (GEBV). A predicted genetic variance (VG ) of reduced magnitude was observed in the twenty crosses with highest midparent GEBV or µSP for HIR. Our results indicate that although GP is a useful tool for parental selection, decisions about which cross combinations should be pursued need to be based on optimal trade-offs between maximizing both µSP and VG .


Assuntos
Modelos Genéticos , Zea mays , Genoma , Genômica , Haploidia , Zea mays/genética
14.
Water Sci Technol ; 82(1): 144-156, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32910799

RESUMO

To accelerate the degradation of substrate, 50% liquid digestate recirculation (LDR) was used in the anaerobic digestion (AD) of corn straw. The effects of recirculation on the enzyme activities and biogas production were investigated by comparing with control reactor (ReactorCK). During the AD process, the fermentation system with 50% LDR was more stable. The average biogas and methane production in ReactorLDR were 7,891 mL·d-1 and 347 mL CH4·g-1 VSadded·d-1 respectively. The total volatile fatty acids (TVFAs) concentration in the two reactors both increased at first and then decreased with time. The LDR made the VFAs accumulation significant, especially propionic acid accumulation in 4 ∼ 16 days. The maximum peak value of cellulase, xylanase, dehydrogenase and coenzyme F420 activities in ReactorLDR were 0.51 mg·g-1·h-1, 0.29 mg·g-1·h-1, 4.88 mL·g-1·h-1 and 6.69 µmol·L-1, respectively, which were higher than that in ReactorCK. With or without recirculation, the concentration of TVFAs was positively correlated with cellulase, xylanase and dehydrogenase activities, while was negatively correlated with coenzyme F420 activity. Besides, a very significant correlation existed between hydrolase and dehydrogenase activities and daily biogas production in ReactorCK. And the peaks of cellulase, xylanase and dehydrogenase activities appeared ahead of the peak of daily biogas production with the LDR.


Assuntos
Biocombustíveis , Zea mays , Anaerobiose , Ácidos Graxos Voláteis , Fermentação
15.
Sci Total Environ ; 741: 140216, 2020 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-32886998

RESUMO

About 90% of the plastic garbage remains in terrestrial ecosystems, and increasing evidence highlights the exposure of crops to plastic particles. However, the potential bioaccumulation of microplastics by plants and their effects on plants' physiology remains unexplored. Here, we evaluated the adsorption, potential uptake, and physiological effects of polyethylene (PE) microbeads in an experimental hydroponic culture of maize. Using isotope analysis, taking advantage of the different carbon isotope composition (δ13C) of fossil-derived PE and C4 plants (e.g., maize), we estimated that about 30% of the carbon in the rhizosphere of microplastic-exposed plants was derived from PE. Still, we did not find evidence of PE translocation to the shoots. Plastic bioaccumulation in the rhizosphere caused a significant decline in transpiration, nitrogen content, and growth. Our results indicate that plastic particles may accumulate in the rhizosphere, impairing water and nutrient uptake, and eventually reaching root eaters. Due to the implications for food production and livestock feeding, our findings encourage further research on the mechanism leading to the bioaccumulation of microplastics on the surface of belowground tissues.


Assuntos
Polietileno , Poluentes Químicos da Água/análise , Adsorção , Ecossistema , Hidroponia , Microesferas , Plásticos , Zea mays
16.
Sci Total Environ ; 741: 140488, 2020 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-32887004

RESUMO

Nitrogen fertilization significantly increases greenhouse gases (GHGs) emission, when applied from inorganic or organic sources. Minimizing GHGs from agroecosystems without compromising crop yield for stabilization of green production systems remains a challenge. Being an integral component of wheat production technology, the nitrogen (N) application deems to be indispensable. Thus, to reduce the application of N fertilizer and keep in view the minimization of GHGs emission, without compromising soil fertility and wheat production, field experiments were performed with treatments included maize straw mulch (S1: 0, S2: 4500, S3: 9000 kg ha-1) and nitrogen fertilizer (N1: 0, N2: 192 and N3: 240 kg ha-1) during 2015-17. Results showed that the cumulative CO2 and N2O emission from 9000 kg ha-1 of maize straw mulch with 192 kg N ha-1 (S3N2) significantly decreased by 0.67% and 33.7%, respectively, averaged over two years compared with that of 9000 kg ha-1 of maize straw mulch with 240 kg N ha-1 (S3N3). Likewise, the average soil moisture content significantly increased by 10% and 10.6% for S3N2 and S3N3 treatments at 0-10 cm soil depth, respectively, compared to S1N1. Similarly, the S3N2 and S3N3 treatments had lowered the soil temperature by 0.2 and 0.1 °C, respectively, over S1N1 in wheat grown fields. The grain yield of wheat was increased by 45% and 45% under S3N3 and S3N2 treatments than S1N1, respectively. The S3N2 treatment was more economical than S3N3 for wheat crop. Therefore, maize straw mulch (S3) combined with 20% less N fertilizer (N2) from commercial source were considered as a viable production technology to improve crop yield, and reduce soil CO2 and N2O emissions.


Assuntos
Fertilizantes/análise , Triticum , Agricultura , Dióxido de Carbono , China , Nitrogênio/análise , Óxido Nitroso/análise , Solo , Zea mays
17.
Wei Sheng Yan Jiu ; 49(4): 569-573, 2020 Jul.
Artigo em Chinês | MEDLINE | ID: mdl-32928347

RESUMO

OBJECTIVE: To evaluate the effects of genetically modified maize with Cry1Ab and epsps genes on immune function in F3 rats. METHODS: A total of 180 weaning SD rats for F0 generation were randomly divided into three groups, which were treated with AIN-93 G feed control diet, parental maize diet and genetically modified maize diet respectively. After three generations of breeding, antibody producing cells determination, concanavalin A(ConA)-induced lymphocyte transformation test, natural killer(NK)cells activities assay, whole blood lymphocyte subtype detection, delayed type hypersensitivity test and immunity organ index were performed. RESULTS: There were no significant differences between parental maize diet and genetically modified maize diet in terms of the number of antibody-producing cells, ConA-induced spleen lymphocyte proliferation, NK cell activity, whole blood lymphocyte subsets, delayed type hypersensitivity and thymus index(P>0. 05). CONCLUSION: Under the conditions of this experiment, no significant effects were found on immune function of F3 SD rats through the three generation development study of genetically modified maize with CrylAb and epsps genes.


Assuntos
Alimentos Geneticamente Modificados , Zea mays/genética , Animais , Proteínas de Bactérias/genética , Endotoxinas , Proteínas Hemolisinas/genética , Plantas Geneticamente Modificadas , Ratos , Ratos Sprague-Dawley
18.
Anim Sci J ; 91(1): e13454, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-32959464

RESUMO

This study investigated the effects of substituting ear corn silage (ECS) for commercial formula feed on milk production and milk fatty acid profiles in grazing dairy farms during the summer season. A field survey was conducted on five grazing dairy farms in every summer month of 2017, 2018, and 2019. Three of the five farms substituted fresh ECS for the commercial formula feed at a ratio of 2:1 from July of each year (ECS farms). Other farms maintained the same feeding management as before (non-ECS farms). An interview survey was conducted on each farm to calculate feed intake and milk yield per cow. Feed and milk samples were collected in each survey. Milk compositions and milk fatty acid profiles were determined. The substitution of ECS for the commercial formula feed did not affect milk yield or milk composition, but ECS farms maintained low levels of milk urea compared with non-ECS farms (p < .01). The ECS substitution also influenced some of the milk fatty acid proportions; C16:0 and C16:1 increased, and trans-11 C18:1, cis-9,trans-11 C18:2, and the sum of polyunsaturated fatty acids decreased, while these fatty acid proportions were maintained in non-ECS farms throughout the summer season (p < .05).


Assuntos
Ração Animal , Fenômenos Fisiológicos da Nutrição Animal/fisiologia , Bovinos/metabolismo , Bovinos/fisiologia , Indústria de Laticínios , Dieta/veterinária , Suplementos Nutricionais , Ácidos Graxos/análise , Herbivoria/fisiologia , Lactação/fisiologia , Leite/metabolismo , Silagem , Zea mays , Animais , Feminino
19.
Environ Monit Assess ; 192(10): 651, 2020 Sep 22.
Artigo em Inglês | MEDLINE | ID: mdl-32964290

RESUMO

Cadmium (Cd) pollution in plastic shed soils has become increasingly severe, posing a great threat to human health and social stability. Phytoremediation of cadmium pollution is an environmentally friendly and inexpensive remediation method. In this study, maize (Zea mays L.) was selected as the phytoremediation crop by a potted method, and the bioavailability of cadmium was investigated by adding exogenous elemental sulfur. The relationships among the sulfur content, maize growth, cadmium accumulation, and soil parameters were systematically studied. The results showed that, with the supplement of sulfur, the soil pH and activities of soil enzymes (urease, catalase, and sucrase) decreased gradually, and the available heavy metals (Cd, Cr, Zn, and Cu) in soil showed an upward trend. The optimal cadmium enrichment was achieved under T2 by increasing both the biomass of the maize plant and the cadmium concentration in roots and stems. However, T3 and T4 significantly inhibited the growth of maize roots and shoots, leading to a much lower plant biomass compared with that of CK (sulfur-free treatment) and T2. In addition, the cumulative cadmium was not increased because of the low accumulation of cadmium in some parts of the plant. Correlation analyses showed that the sulfur content was negatively correlated with soil pH and maize biomass (P < 0.01), and the cadmium content of whole maize was positively correlated with the dry weight of maize (P < 0.05) and the cadmium content in roots and stems (P < 0.01). In summary, to optimize cadmium phytoremediation of the plastic shed soil, an appropriate concentration of sulfur should be selected in practical applications to ensure that the biomass of the maize is maximized, and the cadmium concentration in different parts of the maize is increased or stabilized.


Assuntos
Cádmio/análise , Poluentes do Solo/análise , Biodegradação Ambiental , Biomassa , Monitoramento Ambiental , Humanos , Raízes de Plantas/química , Plásticos , Solo , Enxofre , Zea mays
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