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1.
Cell Host Microbe ; 28(4): 506-508, 2020 10 07.
Artigo em Inglês | MEDLINE | ID: mdl-33031768

RESUMO

The features that permit or prevent a virus from becoming a zoonotic threat is an ongoing area of investigation. In this issue of Cell Host & Microbe, Herfst et al. and Henritzi et al. help define the molecular and host determinants of influenza virus spillover from animal to human populations.


Assuntos
Vírus da Influenza A , Infecções por Orthomyxoviridae , Orthomyxoviridae , Animais , Humanos , Sus scrofa , Suínos , Zoonoses
2.
Zhongguo Xiu Fu Chong Jian Wai Ke Za Zhi ; 34(10): 1322-1331, 2020 Oct 15.
Artigo em Chinês | MEDLINE | ID: mdl-33063500

RESUMO

Objective: To investigate the effect of hydrogel from acellular porcine adipose tissue (HAPA) on the survival of transplanted adipose tissue. Methods: For in vitro study, adipose tissue and HAPA-adipose tissue complex were cultured in normoxia and hypoxia atmospheres for 24 and 72 hours. TUNEL and Perilipin immunofluorescence staining were performed to observe the effect of HAPA on apoptosis and survival of adipocities. For in vivo study, 42 healthy male nude mice (4-6 weeks old) weighing 15-18 g were randomly divided into adipose group (group A), 10%HAPA group (group B), 20%HAPA group (group C), 30%HAPA group (group D), 40%HAPA group (group E), and 50%HAPA group (group F) according to different HAPA/adipose tissue volume ratio ( n=7). For each group, 1 mL adipose tissue or HAPA-adipose tissue complex was injected subcutaneously into the dorsum of the nude mice. At 4 weeks after transplantation, 7 nude mice in each group were sacrificed and grafts were harvested, gross observation, volume measurement, ultrasound examination, and histologic staining (HE staining, CD31 and Perilipin immunofluorescence stainings) were applied. Results: Hypoxia showed a tendency of promoting adipose tissue necrosis and apoptosis, while HAPA exhibited an obvious effect of inhibiting cell apoptosis in vitro study ( P<0.05). For in vivo study, grafts of all groups had intact fibrocapsule. No obvious signs of infection and necrosis were observed at 4 weeks. Volume shrinkage was observed in all groups, however, the groups A-D had significantly higher volume retention rate than groups E and F ( P<0.05). Ultrasound examination showed that there were no significant difference in the number and volume of liquify area of the grafts in each group ( P>0.05). With the increase of HAPA's volume ratio, HE staining proved an improved fat integrity while a gradually decreased vacuoles and fibrosis. CD31 immunohistochemical staining showed that the number of neo-vascularisation in groups E and F were significantly higher than those in groups A-D ( P<0.05). Perilipin immunofluorescence staining showed that with the increase of HAPA volume ratio, the number of living adipocytes increased gradually, and more new adipocytes could be seen in the field of vision. Conclusion: As the volume ratio of HAPA gradually increased, the survival of transplanted adipose tissue also increased, but the volume retention rate decreased gradually. 30%HAPA was considered the relative optimal volume ratio for its superior adipose tissue survival and volume retation rate.


Assuntos
Hidrogéis , Transplantes , Adipócitos , Tecido Adiposo , Animais , Masculino , Camundongos , Camundongos Nus , Suínos
3.
Rev Sci Tech ; 39(2): 591-598, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-33046917

RESUMO

The first recorded outbreak of African swine fever (ASF) was confirmed in the People's Republic of China in early August 2018. By the end of July 2019, there had been 150 outbreaks of ASF in 31 provinces, including 146 in domestic pigs and four in wild boar. The Chinese Government attaches great importance to the prevention and control of ASF. The Chinese animal health authority promptly launched the highest-priority emergency response against this key animal disease; initiated an extensive surveillance network covering all provinces; formulated and promulgated supporting policies, such as compensation for culled animals and financial credit for affected producers; and established a joint coordination body for ASF prevention and control, led by the Ministry of Agriculture and Rural Affairs and involving a further 20 Ministries, including the Departments of Transportation, Customs and Market Supervision. All levels of local government undertook territorial management responsibilities and developed support policies to encourage all stakeholders to take part in ASF prevention and control. Furthermore, the Chinese Government developed a strategy that integrated both the legal and scientific aspects of ASF control, formulating and releasing a comprehensive policy for the whole pork production chain 'from farm to fork'. The plan included daily disease reports from the disease monitoring network, and adopted effective measures, such as blockades and culling, restricting live pig movements and implementing controls on swill feeding, to cut off viral transmission routes to the greatest extent possible.


Assuntos
Vírus da Febre Suína Africana , Febre Suína Africana , Defesa Civil , Doenças dos Suínos , Febre Suína Africana/epidemiologia , Febre Suína Africana/prevenção & controle , Animais , China/epidemiologia , Sus scrofa , Suínos
4.
Rev Sci Tech ; 39(2): 417-425, 2020 Aug.
Artigo em Espanhol, Inglês | MEDLINE | ID: mdl-33046933

RESUMO

This case study outlines the actions of Cuba's Veterinary Service, as part of the country's disaster risk reduction and management system, in response to Hurricane Irma. The phenomenon affected ten of Cuba's 15 provinces and caused significant damage in 53 of its municipalities (29.6%). During the response effort, the pre-established measures for the various phases (warning, alert and emergency) were deployed according to the disaster reduction plans for each level. In all provinces, animals were protected by moving them to safer locations, allowing for pre-established sanitary measures and technical assistance. Nonetheless, damage was incurred, mainly to the roofs of some animal housing. The following deaths were recorded: 210,150 poultry, 2,752 cattle (of which 73.8% were calves) and 866 pigs (of which 68% were young animals). In addition, 7% of the inventory of hives was damaged and 3.3% of hives were lost. Damage to infrastructure included: 466 poultry houses, 1,422 cattle houses, 431 pig houses, 1,200 wind pumps and 13 of the country's 17 feed concentrate plants. As no major damage was reported to the Veterinary Service's facilities (laboratories and offices), its viability was guaranteed at all times. Rapid damage assessment enabled priorities for rehabilitation and recovery actions to be set, with the result that, just three months after the hurricane had struck, 67% of the poultry houses and 33% of the pig houses had been restored. This article focuses on preparedness, response and lessons learned.


Assuntos
Tempestades Ciclônicas , Planejamento em Desastres , Desastres , Animais , Bovinos , Cuba , Abrigo para Animais , Suínos
5.
Annu Int Conf IEEE Eng Med Biol Soc ; 2020: 382-385, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-33018008

RESUMO

An elevated heart rate (HR) often persists in resuscitated septic shock patients, increasing the risk of mortality. Several drugs for HR control, such as esmolol and ivabradine, have been tested in the recent years, but their benefit on the overall cardiovascular system is still under investigation. The aim of this study is to investigate the hemodynamic effects of the two drugs in a protocol of polymicrobial septic shock and resuscitation, mainly focusing on the vascular function. Twelve pigs were divided into three experimental groups: the esmolol-treated group (n=4), the ivabradine-treated group (n=5) and the control group (n=3). The characteristic arterial time constant τ was computed on aortic arterial pressure (AoP), together with estimates of total arterial compliance and peripheral resistance. Power spectral analysis of aortic and radial diastolic BP oscillations was performed to estimate the sympathetic autonomic control of vascular tone. Septic shock induced a severe cardiac and vascular disarray, only partially resolved by resuscitation. The administration of esmolol, but not ivabradine, was beneficial both for cardiac and vascular function, thereby its adjunction to standard therapies could help to improve patient's condition and optimize the resuscitation strategies.Clinical Relevance-This study shows a potential beneficial effect of esmolol on the arterial tree.


Assuntos
Propanolaminas , Choque Séptico , Animais , Humanos , Ivabradina , Propanolaminas/farmacologia , Choque Séptico/tratamento farmacológico , Suínos , Taquicardia/tratamento farmacológico
6.
Annu Int Conf IEEE Eng Med Biol Soc ; 2020: 837-840, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-33018115

RESUMO

Gastric motility is in part coordinated by bio-electrical slow waves. The wavefront orientation of the slow wave contains vital physiological information about the motility condition of the gastrointestinal system. Dysmotility was shown to be associated with dysrhythmic propagation of the slow wave. The most commonly used method to detect wavefront orientation is computationally expensive because of the involvement of activation time identification. The information of local directionality contained in bipolar slow wave recordings could be used to detect the wavefront orientation. An algorithm called bipolar direction detection was developed to utilize the information contained in the bipolar slow wave recordings. Bipolar recordings were constructed by subtracting the unipolar in vivo recordings of directional electrode pairs. Then, time delay information was used to detect the wavefront direction. The algorithm was verified using synthetic data and validated using experimental data. Ten high-resolution in vivo slow wave signals from 5 pigs were recorded for a duration of 2 minutes. The performance was compared against the semi-automated approach, resulting in an average angle error of 20° for the experimental data. The algorithm was able to detect slow wave wavefront orientation with minimal errors rapidly.Clinical relevance-The ability to rapidly detect slow wave propagation direction will enable effective analysis of large data sets, through which we can obtain a better understanding of functional motility disorders and help with diagnosis and treatment.


Assuntos
Transtorno Bipolar , Estômago , Algoritmos , Animais , Transtorno Bipolar/diagnóstico , Eletrodos , Reprodução , Suínos
7.
Annu Int Conf IEEE Eng Med Biol Soc ; 2020: 1436-1439, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-33018260

RESUMO

Gastric motility disorders are associated with bioelectrical abnormalities in the stomach. Recently, gastric ablation has emerged as a potential therapy to correct gastric dysrhythmias. However, the tissue-level effects of gastric ablation have not yet been evaluated. In this study, radiofrequency ablation was performed in vivo in pigs (n=7) at temperature-control mode (55-80°C, 5-10 s per point). The tissue was excised from the ablation site and routine H&E staining protocol was performed. In order to assess tissue damage, we developed an automated technique using a fully convolutional neural network to segment healthy tissue and ablated lesion sites within the muscle and mucosa layers of the stomach. The tissue segmentation achieved an overall Dice score accuracy of 96.18 ± 1.0 %, and Jacquard score of 92.77 ± 1.9 %, after 5-fold cross validation. The ablation lesion was detected with an overall Dice score of 94.16 ± 0.2 %. This method can be used in combination with high-resolution electrical mapping to define the optimal ablation dose for gastric ablation.Clinical Relevance-This work presents an automated method to quantify the ablation lesion in the stomach, which can be applied to determine optimal energy doses for gastric ablation, to enable clinical translation of this promising emerging therapy.


Assuntos
Aprendizado Profundo , Redes Neurais de Computação , Animais , Músculos , Estômago/diagnóstico por imagem , Suínos , Vísceras
8.
Annu Int Conf IEEE Eng Med Biol Soc ; 2020: 1779-1782, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-33018343

RESUMO

Gastrointestinal (GI) motility and functional disorders affect up to 25% of the American population. Electrophysiological studies had shown a link between these functional motility disorders and abnormalities in GI bioelectrical activity. However, the dynamics between GI electrical activity (slow waves and spike bursts) and motility are not well understood. This study presents a framework to simultaneously record and quantify GI spike bursts and motility in vivo, in high-resolution. The dynamics between spike burst events and motility observed in 4 pig studies were investigated. A clear connection between spike burst patches and localized contractions was observed. The dataset consisted of 685 spike burst events in 191 patches. Contractions were associated with 81 patches. Spike burst patches associated with contractions had significantly higher amplitude, duration, and size compared to the ones that did not show an association. The amplitude, duration, and size of spike burst patches were positively correlated with the contraction strength. The spike burst patch energy displayed the highest correlation (r = 0.74). The contraction strength had a linear trend with spike burst patch energy. However, it could only account for 52% of the variance in contraction strength.


Assuntos
Motilidade Gastrointestinal , Intestinos , Animais , Duodeno , Jejuno , Suínos
9.
Annu Int Conf IEEE Eng Med Biol Soc ; 2020: 1859-1862, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-33018362

RESUMO

Quantitative descriptions of the morphology and structure of peripheral nerves is central in the development of bioelectronic devices interfacing the nerves. While histological procedures and microscopy techniques yield high-resolution detailed images of individual axons, automated methods to extract relevant information at the single-axon level are not widely available. We implemented a segmentation algorithm that allows for subsequent feature extraction in immunohistochemistry (IHC) images of peripheral nerves at the single fiber scale. These features include short and long cross-sectional diameters, area, perimeter, thickness of surrounding myelin and polar coordinates of single axons within a nerve or nerve fascicle. We evaluated the performance of our algorithm using manually annotated IHC images of 27 fascicles of the swine cervical vagus; the accuracy of single-axon detection was 82%, and of the classification of fiber myelination was 89%.


Assuntos
Axônios , Nervos Periféricos , Animais , Estudos Transversais , Microscopia , Bainha de Mielina , Suínos
10.
Annu Int Conf IEEE Eng Med Biol Soc ; 2020: 2438-2441, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-33018499

RESUMO

We have created a lung simulation to quantify lung heterogeneity from the results of the inspired sinewave test (IST). The IST is a lung function test that is non-invasive, non-ionising and does not require patients' cooperation. A tidal lung simulation is developed to assess this test and also a method is proposed to calculate lung heterogeneity from IST results. A sensitivity analysis based on the Morris method and linear regression were applied to verify and to validate the simulation. Additionally, simulated emphysema and pulmonary embolism conditions were created using the simulation to assess the ability of the IST to identify these conditions. Experimental data from five pigs (pre-injured vs injured) were used for validation. This paper contributes to the development of the IST. Firstly, our sensitivity analysis reveals that the IST is highly accurate with an underestimation of about 5% of the simulated values. Sensitivity analysis suggested that both instability in tidal volume and extreme expiratory flow coefficients during the test cause random errors in the IST results. Secondly, the ratios of IST results obtained at two tracer gas oscillation frequencies can identify lung heterogeneity (ELV60/ELV180 and Qp60/Qp180). There was dissimilarity between simulated emphysema and pulmonary embolism (p < 0.0001). In the animal model, the control group had ELV60/ELV180 = 0.58 compared with 0.39 in injured animals (p < 0.0001).


Assuntos
Pulmão , Animais , Humanos , Testes de Função Respiratória , Suínos , Volume de Ventilação Pulmonar
11.
Annu Int Conf IEEE Eng Med Biol Soc ; 2020: 2552-2556, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-33018527

RESUMO

Mitral valve regurgitation is one of the most common heart valve diseases and mitral valve repair is the favored therapy, in which a part of the mitral valve is resected. To improve preoperative planning of this challenging surgery, patient-specific mitral valve replicas have been developed on which the repair can be simulated. However, there is no possibility yet to transfer the planning from the replica to the surgery of the patient. To solve this problem, we developed a patient-specific instrument with a cutting template, intraoperatively visualizing the part of the mitral valve to be resected as planned on the replica. To realize this instrument, the surgeon first simulates mitral valve repair by resection on a patient-specific mitral valve replica. This postoperative mitral valve replica is then digitalized and from it and a preoperative mitral valve model the instrument with cutting template is automatically designed and then 3D printed. An expert heart surgeon successfully tested the functional principle of the instrument on a pig mitral valve.


Assuntos
Procedimentos Cirúrgicos Cardíacos , Doenças das Valvas Cardíacas , Insuficiência da Valva Mitral , Cirurgiões , Animais , Humanos , Valva Mitral/cirurgia , Insuficiência da Valva Mitral/cirurgia , Suínos
12.
Annu Int Conf IEEE Eng Med Biol Soc ; 2020: 2756-2759, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-33018577

RESUMO

Persisting tachycardia is often observed in resuscitated septic shock patients, and it is an independent risk factor for increased mortality. Recently, several drugs, such as esmolol and ivabradine, have been proved to be beneficial in HR control, but their overall impact on cardiac functions needs further investigation. The aim of this study is to study the effects of the two drugs on heart function in a protocol of polymicrobial septic shock and resuscitation. Twelve pigs were divided into three experimental groups: the esmolol-treated group (n=4), the ivabradine-treated group (n=5) and the control group (n=3). Cardiac autonomic activity was estimated by heart rate variability (HRV) indices and baroreflex sensitivity (BRS). The Buckberg index was adopted to evaluate myocardial oxygenation efficiency. Septic shock induced a severe autonomic dysfunction and a lower cardiac efficiency, not resolved by fluids resuscitation. The administration of the drugs improved both the HRV and the BRS, but this favourable condition was preserved after noradrenaline administration only in the esmolol group. The interaction of esmolol with the autonomic system is beneficial in septic shock to restore an improved condition of HRV and control, while ivabradine is not as effective when administered in adjunction to noradrenaline.


Assuntos
Propanolaminas , Choque Séptico , Animais , Humanos , Ivabradina/uso terapêutico , Propanolaminas/uso terapêutico , Choque Séptico/tratamento farmacológico , Suínos , Taquicardia/tratamento farmacológico
13.
Annu Int Conf IEEE Eng Med Biol Soc ; 2020: 2816-2819, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-33018592

RESUMO

In this computational modelling work, we explored the mechanical roles that various glycosaminoglycans (GAGs) distributions may play in the porcine ascending aortic wall, by studying both the transmural residual stress as well as the opening angle in aortic ring samples. A finite element (FE) model was first constructed and validated against published data generated from rodent aortic rings. The FE model was then used to simulate the response of porcine ascending aortic rings with different GAG distributions prescribed through the wall of the aorta. The results indicated that a uniform GAG distribution within the aortic wall did not induce residual stresses, allowing the aortic ring to remain closed when subjected to a radial cut. By contrast, a heterogeneous GAG distribution led to the development of residual stresses which could be released by a radial cut, causing the ring to open. The residual stresses and opening angle were shown to be modulated by the GAG content, gradient, and the nature of the transmural distribution.


Assuntos
Aorta , Glicosaminoglicanos , Túnica Adventícia , Animais , Valva Aórtica , Estresse Mecânico , Suínos
14.
Physiol Meas ; 41(9): 095011, 2020 10 09.
Artigo em Inglês | MEDLINE | ID: mdl-33035199

RESUMO

OBJECTIVE: The target of this methodological evaluation was the feasibility of long-term monitoring of changes in lung conditions by time-difference electrical impedance tomography (tdEIT). In contrast to ventilation monitoring by tdEIT, the monitoring of end-expiratory (EELIC) or end-inspiratory (EILIC) lung impedance change always requires a reference measurement. APPROACH: To determine the stability of the used Pulmovista 500® EIT system, as a prerequisite it was initially secured on a resistive phantom for 50 h. By comparing the slopes of EELIC for the whole lung area up to 48 h from 36 pigs ventilated at six positive end-expiratory pressure (PEEP) levels from 0 to 18 cmH2O we found a good agreement (range of r 2 = 0.93-1.0) between absolute EIT (aEIT) and tdEIT values. This justified the usage of tdEIT with its superior local resolution compared to aEIT for long-term determination of EELIC. MAIN RESULTS: The EELIC was between -0.07 Ωm day-1 at PEEP 4 and -1.04 Ωm day-1 at PEEP 18 cmH2O. The complex local time pattern for EELIC was roughly quantified by the new parameter, centre of end-expiratory change (CoEEC), in equivalence to the established centre of ventilation (CoV). The ventrally located mean of the CoV was fairly constant in the range of 42%-46% of thorax diameter; however, on the contrary, the CoEEC shifted from about 40% to about 75% in the dorsal direction for PEEP levels of 14 and 18 cmH2O. SIGNIFICANCE: The observed shifts started earlier for higher PEEP levels. Changes of EELI could be precisely monitored over a period of 48 h by tdEIT on pigs.


Assuntos
Monitorização Fisiológica , Tomografia , Lesão Pulmonar Induzida por Ventilação Mecânica/diagnóstico por imagem , Lesão Pulmonar Induzida por Ventilação Mecânica/fisiopatologia , Animais , Impedância Elétrica , Expiração , Suínos , Fatores de Tempo
15.
Int J Esthet Dent ; 15(4): 454-473, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33089260

RESUMO

Ridge defects are a very common finding after tooth extraction. Recent literature has shown that the pattern of bone and soft tissue remodeling can obtain up to 50% of the original volume. Many different surgical approaches have been proposed over the years to correct ridge defects, but the results have often been inconsistent or difficult to reproduce on a daily basis. For some time, surgeons have relied on the guided bone regeneration (GBR) technique, taking advantage of a barrier membrane to protect the blood clot, combined with different combinations of autogenous bone and bone grafts from various sources. If some kind of understanding has been reached and certain guidelines adopted for the treatment of horizontal defects, those for tridimensional and vertical defects still present a challenge. About a decade ago, a new biomaterial became available on the market - a membrane made of collagenated porcine bone called cortical lamina - which proved to be reliable and easy to handle for both horizontal and vertical defects. The aim of this article is to review the current literature on the topic and to discuss the material in its three forms through the presentation of three patient cases of differing complexity, each with its unique indications and characteristics.


Assuntos
Aumento do Rebordo Alveolar , Animais , Regeneração Óssea , Transplante Ósseo , Implantação Dentária Endo-Óssea , Regeneração Tecidual Guiada Periodontal , Humanos , Suínos
16.
J Environ Qual ; 49(1): 27-37, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33016358

RESUMO

The United States, particularly the southern portion, has recently suffered drastic population expansion of wild pigs causing destruction of prime farmland. An associated concern, which has been understudied, is the potential transfer of nutrients and pathogens to surface water. This study aimed to identify the abiotic and biotic impacts of captive wild pigs on water quality, including nutrients, fecal indicator and pathogenic bacteria, and antimicrobial resistance. Overall, the study demonstrated that wild pigs harbored Salmonella spp., Campylobacter spp., Escherichia coli, and Clostridium perfringens, which were found in water runoff collected directly beneath the hog paddock, often 2 log10 greater than above-paddock levels. However, the impacts to downstream water quality were limited, perhaps because of a relatively large riparian buffer between the paddock and surface water. A higher rate of ammonium concentration changes over time was detected in the runoff water below the paddock; additionally, microbial releases detected in runoff were also time dependent, possibly associated with increasing pig numbers. Antibiotic resistance was generally not associated with the wild pigs. Antibiotic resistance genes were found in upstream as well as downstream surface water, suggesting that nonpoint sources of microbial contamination were present. Interestingly, intI1 levels were greater in below-paddock runoff by nearly 2 log10 . Overall, it appears that wild pigs potentially pose a threat to water quality but only if they have direct access to the water. Pathogen, fecal indicator bacteria, and some nutrient release were significantly associated with wild pigs, but riparian buffers limited water quality impairment.


Assuntos
Bactérias , Qualidade da Água , Animais , Antibacterianos , Escherichia coli , Fezes , Suínos , Estados Unidos
17.
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
18.
J Environ Qual ; 49(3): 754-761, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-33016404

RESUMO

Land application of manure introduces gastrointestinal microbes into the environment, including bacteria carrying antibiotic resistance genes (ARGs). Measuring soil ARGs is important for active stewardship efforts to minimize gene flow from agricultural production systems; however, the variety of sampling protocols and target genes makes it difficult to compare ARG results between studies. We used polymerase chain reaction (PCR) methods to characterize and/or quantify 27 ARG targets in soils from 20 replicate, long-term no-till plots, before and after swine manure application and simulated rainfall and runoff. All samples were negative for the 10 b-lactamase genes assayed. For tetracycline resistance, only source manure and post-application soil samples were positive. The mean number of macrolide, sulfonamide, and integrase genes increased in post-application soils when compared with source manure, but at plot level only, 1/20, 5/20, and 11/20 plots post-application showed an increase in erm(B), sulI, and intI1, respectively. Results confirmed the potential for temporary blooms of ARGs after manure application, likely linked to soil moisture levels. Results highlight uneven distribution of ARG targets, even within the same soil type and at the farm plot level. This heterogeneity presents a challenge for separating effects of manure application from background ARG noise under field conditions and needs to be considered when designing studies to evaluate the impact of best management practices to reduce ARG or for surveillance. We propose expressing normalized quantitative PCR (qPCR) ARG values as the number of ARG targets per 100,000 16S ribosomal RNA genes for ease of interpretation and to align with incidence rate data.


Assuntos
Esterco , Solo , Animais , Antibacterianos/farmacologia , Produtos Agrícolas , Resistência Microbiana a Medicamentos/genética , Microbiologia do Solo , Suínos
19.
J Environ Qual ; 49(5): 1384-1395, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-33016445

RESUMO

Nutrients excreted from animals affect the nutritive value of manure as a soil amendment as well as the composition of gases emitted from manure storage facilities. There is a dearth of information, however, on how diet type in combination with dietary particle size affects nutrients deposited into manure storage facilities and how this affects manure composition and gas emissions. To fill this knowledge gap, an animal feeding trial was performed to evaluate potential interactive effects between feed particle size and diet composition on manure characteristics and manure-derived gaseous emissions. Forty-eight finishing pigs housed in individual metabolism crates that allowed for daily collection of urine and feces were fed diets differing in fiber content and particle size. Urine and feces were collected and stored in 446-L stainless steel containers for 49 d. There were no interactive effects between diet composition and feed particle size on any manure or gas emission parameter measured. In general, diets higher in fiber content increased manure nitrogen (N), carbon (C), and total volatile fatty acid (VFA) concentrations and increased manure VFA emissions but decreased manure ammonia emissions. Decreasing the particle size of the diet lowered manure N, C, VFAs, phenolics, and indole concentrations and decreased manure emissions of total VFAs. Neither diet composition nor particle size affected manure greenhouse gas emissions.


Assuntos
Dieta/veterinária , Esterco , Ração Animal/análise , Animais , Gases , Tamanho da Partícula , Suínos
20.
J Environ Qual ; 49(5): 1435-1444, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-33016451

RESUMO

Chlortetracycline (CTC), an antimicrobial administered as a feed additive to cattle, swine, and poultry, is present in the corresponding manure. Land application of raw or processed (composted or stockpiled) manure provides a mechanism by which CTC (and other antimicrobials) enters the environment and becomes available for transport to surface receiving waters via rainfall or snowmelt runoff. Chlortetracycline has been detected in Canadian surface waters, but little has been reported on its fate in aquatic ecosystems. To address this knowledge gap, the dissipation of CTC-enol was monitored in deionized water and water typical of wetlands within the prairie region of Canada. In deionized water, CTC-enol tautomerized to CTC-keto, and both tautomers epimerized to 4-epi-CTC-enol and 4-epi-CTC-keto, respectively. Irreversible isomerization to iso-CTC occurred, which then epimerized to 4-epi-iso-CTC. In wetland water, although tauterization of CTC-enol to CTC-keto occurred, there was no evidence of the formation of the 4-epimers of either CTC-enol or CTC-keto. The major product formed in the wetland water was iso-CTC, some of which epimerized to 4-epi-iso-CTC. Although CTC-enol was shown to tautomerize to CTC-keto, the concentration of CTC-keto remained low in both deionized and wetland water, suggesting that the isomerization of CTC-enol to iso-CTC most likely occurred via CTC-keto. The dissipation of CTC-enol in wetland water was described by pseudo first-order kinetics with a DT50 (time required for 50% dissipation) value of 4.8 h. The short DT50 value of CTC and reduced antimicrobial activity of iso-CTC and 4-epi-iso-CTC suggest a lower probability for selection for CTC-resistant bacteria in Canadian Prairie aquatic ecosystems.


Assuntos
Clortetraciclina , Animais , Canadá , Bovinos , Ecossistema , Pradaria , Isomerismo , Suínos , Áreas Alagadas
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