Project description:Dairy cattle of different ages experience different living conditions and varied frequency of antibiotic administration that likely influence the distribution of microbiome and resistome in ways that reflect different risks of microbial transmission. To assess the degree of variance in these distributions, fecal and soil samples were collected from six distinct housing areas on commercial dairy farms (n = 7) in Washington State. 16S rRNA gene sequencing indicated that the microbiota differed between different on-farm locations in feces and soil, and in both cases, the microbiota of dairy calves was often distinct from others (P < 0.05). Thirty-two specific antibiotic resistance genes (ARGs) were widely distributed on dairies, of which several clinically relevant ARGs (including cfr, cfrB, and optrA) were identified for the first time at U.S. dairies. Overall, ARGs were observed more frequently in feces and soil from dairy calves and heifers than from hospital, fresh, lactation and dry pens. Droplet-digital PCR demonstrated that the absolute abundance of floR varied greatly across housing areas and this gene was enriched the most in calves and heifers. Furthermore, in an extended analysis with 14 dairies, environmental soils in calf pens had the most antibiotic-resistant Escherichia coli followed by heifer and hospital pens. All soil E. coli isolates (n = 1,905) are resistant to at least 4 different antibiotics, and the PFGE analysis indicated that florfenicol-resistant E. coli is probably shared across geographically-separated farms. This study identified a discrete but predictable distribution of antibiotic resistance genes and organisms, which is important for designing mitigation for higher risk areas on dairy farms.
Project description:Evaluation of agricultural intensification requires comprehensive analysis of trends in farm performance across physical and socio-economic aspects, which may diverge across farm types. Typical reporting of economic indicators at sectorial or the "average farm" level does not represent farm diversity and provides limited insight into the sustainability of specific intensification pathways. Using farm business data from a total of 7281 farm survey observations of English and Welsh dairy farms over a 14-year period we calculate a time series of 16 key performance indicators (KPIs) pertinent to farm structure, environmental and socio-economic aspects of sustainability. We then apply principle component analysis and model-based clustering analysis to identify statistically the number of distinct dairy farm typologies for each year of study, and link these clusters through time using multidimensional scaling. Between 2001 and 2014, dairy farms have largely consolidated and specialized into two distinct clusters: more extensive farms relying predominantly on grass, with lower milk yields but higher labour intensity, and more intensive farms producing more milk per cow with more concentrate and more maize, but lower labour intensity. There is some indication that these clusters are converging as the extensive cluster is intensifying slightly faster than the intensive cluster, in terms of milk yield per cow and use of concentrate feed. In 2014, annual milk yields were 6,835 and 7,500 l/cow for extensive and intensive farm types, respectively, whilst annual concentrate feed use was 1.3 and 1.5 tonnes per cow. For several KPIs such as milk yield the mean trend across all farms differed substantially from the extensive and intensive typologies mean. The indicators and analysis methodology developed allows identification of distinct farm types and industry trends using readily available survey data. The identified groups allow the accurate evaluation of the consequences of the reduction in dairy farm numbers and intensification at national and international scales.
Project description:Thermoactinomyces species are heat-resistant spore-forming bacteria that are capable of producing proteases. Here, we report the draft genome sequence of a new Thermoactinomyces vulgaris strain, AGRTWHS02, with a strong proteolytic activity, which was isolated from a sheep dairy farm environment in New Zealand. The genome is 2.56 Mbp, with a GC content of 47.9%.
Project description:Antimicrobials are used in animal agriculture to cure bacterial infectious diseases. However, antimicrobial use (AMU) inevitably leads to the selection of resistant bacteria, potentially infecting humans. As a global public threat, antimicrobial resistance has led policy makers to implement regulations supervising AMU. The objective of our research was to investigate the farm impact of several potential policies aimed at decreasing AMU. We modeled a dairy herd of 1000 cows with an average level of disease prevalence for the nine most frequent bacterial dairy diseases found in western countries. We calculated the farm net costs of AMU prohibition, as well as cost increases in antimicrobial treatments prices, and an increase in the milk withdrawal period after AMU. Sensitivity analyses were conducted to assess the impact of output and input prices, and disease prevalence. At a mean disease prevalence, the average net costs of not using antimicrobials were $61 per cow per year greater compared to a scenario modeling current farm AMU. The model predicted that the minimum and maximum increased costs associated with AMU prohibition were $46 and $73 per cow per year compared to current AMU. In each scenario, the cost difference increased with disease prevalence. Sensitivity analysis showed that the three stochastic variables which most significantly influenced the cost difference were respectively, cow replacement prices, cow slaughter price, and the milk price. Antimicrobial price increases of a factor of five, or extending the milk withdrawal period by 15 days, resulted in increasing the costs of diseases to a level where the farmer was better off not using antimicrobials. Our results suggest that the farm level costs of AMU prohibition in many cases might be minor, although the consequences of any policy instrument should be carefully evaluated to reach the ultimate goal of decreasing AMU without threatening the sustainability of milk production.
Project description:The environmental impacts of the dairy industry, particularly global warming, are heavily influenced by milk production. Thus, there is an urgent need for farm-level actions and opportunities for improvement, implying mitigation strategies. The aim of this paper is to investigate five possible mitigation actions at the dairy farm and which one the farmers were willing to adopt: management and distribution of livestock manure and fertilizers, anaerobic manure treatment, optimization of the herd composition, feed quality, and heat recovery. A life cycle assessment was conducted on 63 farms using the product environmental footprint approach. The latter was divided into four quartiles, from which four representative farms were selected. For each farm, three scenarios have been analyzed considering the reference impact (reference scenario), the application of the mitigation actions (best-case scenario), and what farmers would implement (realistic scenario). Overall, the most effective mitigation actions in the best-case scenario were anaerobic manure treatment and the management and distribution of livestock manure and fertilizers, showing a potential reduction in total environmental impacts of 7-9% and 6-7%, respectively. Farmers' responses indicated a willingness to implement the latter mitigation strategy better. The optimization of the herd composition, feed quality, and heat recovery reported a range impact reduction between 0.01-5%.
Project description:The use of antibiotics in animal husbandry contributes to the worldwide problem of increasing antibiotic resistance in animal and human pathogens. Intensive animal production is considered an important source of antibiotic resistance genes released to the environment, while the contribution of smaller farms remains to be evaluated. Here we monitor the spread of tetracycline resistance (TC-r) genes at a middle-size conventional dairy farm, where chlortetracycline (CTC, as intrauterine suppository) is prophylactically used after each calving. Our study has shown that animals at the farm acquired the TC-r genes in their early age (1-2 weeks), likely due to colonization with TC-resistant bacteria from their mothers and/or the farm environment. The relative abundance of the TC-r genes tet(W), tet(Q), and tet(M) in fresh excrements of calves was about 1-2 orders of magnitude higher compared to heifers and dairy cows, possibly due to the presence of antibiotic residues in milk fed to calves. The occurrence and abundance of TC-r genes in fresh excrements of heifers and adult cows remained unaffected by intrauterine CTC applications, with tet(O), tet(Q), and tet(W) representing a "core TC-resistome" of the farm, and tet(A), tet(M), tet(Y), and tet(X) occurring occasionally. The genes tet(A), tet(M), tet(Y), and tet(X) were shown to be respectively harbored by Shigella, Lactobacillus and Clostridium, Acinetobacter, and Wautersiella. Soil in the farm proximity, as well as field soil to which manure from the farm was applied, was contaminated with TC-r genes occurring in the farm, and some of the TC-r genes persisted in the field over 3 months following the manure application. Concluding, our study shows that antibiotic resistance genes may be a stable part of the intestinal metagenome of cattle even if antibiotics are not used for growth stimulation, and that smaller dairy farms may also contribute to environmental pollution with antibiotic resistance genes.
Project description:The aim of this study was to describe the gene expression patterns related to the differentiation and mineralization of bone-forming cells, including activation and/or repression of osteogenic or non-osteogenic pathways, remodeling of cell architecture, cell adhesion, cell communication, and assembly of extracellular matrix. The study implied patient selection, tissue collection, isolation and culture of human marrow stromal cells (hMSC) and osteoblasts (hOB), and characterization of bone-forming cells. RNA samples were collected at defined time points, in order to understand the regulation of gene expression during the processes of cell differentiation/mineralization that occur during bone repair. Transcriptome analysis was performed by using the Affymetrix GeneChip microarray technology platform and GeneChip Human Genome U133 Plus 2.0 Array. Our results help to design a gene expression profile of bone-forming cells during specific steps of osteogenic differentiation. These findings offer an useful tool to monitor the behaviour of osteogenic precursors cultured in presence of exogenous stimuli, i.e. growth factors, or onto 3D scaffolds for bone engineering. Moreover, they can contribute to identify and clarify the role of new genes for a better understanding of the molecular mechanisms regulating osteogenesis. Experiment Overall Design: Differentiated osteoblasts (hOB) were obtained from trabecular bone fragments of four patients. hOB cultures were maintained in mineralization medium containing beta-glycerophosphate, and collected at different time points. The experimental protocol was specifically devised to mark four steps of hOB mineralization (HM). The reference sample consisted in confluent hOBs before the addition of mineralization medium (HM1).
Project description:The aim of this study was to describe the gene expression patterns related to the differentiation and mineralization of bone-forming cells, including activation and/or repression of osteogenic or non-osteogenic pathways, remodeling of cell architecture, cell adhesion, cell communication, and assembly of extracellular matrix. The study implied patient selection, tissue collection, isolation and culture of human marrow stromal cells (hMSC) and osteoblasts (hOB), and characterization of bone-forming cells. RNA samples were collected at defined time points, in order to understand the regulation of gene expression during the processes of cell differentiation/mineralization that occur during bone repair. Transcriptome analysis was performed by using the Affymetrix GeneChip microarray technology platform and GeneChip® Human Genome U133 Plus 2.0 Array. Our results help to design a gene expression profile of bone-forming cells during specific steps of osteogenic differentiation. These findings offer an useful tool to monitor the behaviour of osteogenic precursors cultured in presence of exogenous stimuli, i.e. growth factors, or onto 3D scaffolds for bone engineering. Moreover, they can contribute to identify and clarify the role of new genes for a better understanding of the molecular mechanisms regulating osteogenesis. Experiment Overall Design: hMSC were obtained from bone marrow aspirates of four patients. hMSC cultures were maintained in mineralization medium containing β-glycerophosphate, and collected at different time points. The experimental protocol was specifically devised to mark three steps of hMSC mineralization (MM). The reference sample consisted in confluent hMSCs before the addition of mineralization medium (MD4).