Global antimicrobial use in livestock farming: an estimate for cattle, chickens, and pigs

Livestock farming substantially contributes to the global economy and food security. However, it poses crucial environmental, animal welfare, and public health challenges. The main objective of this study is to quantify the global antimicrobial use (AMU) in cattle, chicken, and pig farming. This information is important for understanding the potential impact of farm AMU on the emergence and spread of antimicrobial resistance among animals and humans. Using the United States Department of Agriculture Production, Supply, and Distribution and the Food and Agriculture Organization databases, we estimated the total supply of cattle (in heads) and its distribution into four weight categories: calves (26%), cows (41%), heifers (4%), and bulls of more than one year (29%). Similarly, we calculated the total supply of pigs (in heads) and divided it into two weight categories: pigs (96%) and sows (4%). For chickens, we considered one weight category. We attributed to each category a standard weight according to the parameters set by the European Medicines Agency (EMA) to determine the animal biomass at risk of antimicrobial treatment, or population correction unit (PCU). Finally, we estimated the global PCUs and then the global AMU based on the average administered to the three species (in mg of active ingredients per kg PCU). With this method, we estimated a global annual AMU of 76 060 tonnes of antimicrobial active ingredients (2019-2021 average), of which 40 697 tonnes (or 53.5%) for cattle, 4 243 tonnes (or 5.6%) for chickens, and 31 120 tonnes (or 40.9%) for pigs. According to our assessment, global AMU leads to almost 20 000 tonnes less than the previous estimates due to a different evaluation of PCUs. In previous studies, PCUs were calculated on the liveweight at slaughtering of animals, while our method considers the age and sex of animals and their average weight at treatment. Our results are consistent with the World Organization for Animal Health (WOAH) estimate of 76 704 tonnes of veterinary antimicrobials globally consumed in 2018 for the total of food-producing animals (the WOAH estimation is based on sales and import data).

Sustainable Husbandry?-A Comparative LCA of Three Lamb Breeding Systems in Turkey

The agricultural sector has historically been the forefront economic sector in Turkey and is crucial for the rural sustainability and the pastures that are critical for biodiversity. However, inadequate policies and factors such as climate change and malpractices result in brittle pastures, rural-urban migration, and a declining agricultural sector. Also, pastures have been left without function and appropriated to other land uses such as quarries, energy power plants, and mines. Although the husbandry sector produces significant greenhouse gas emissions, pastures have a significant capacity of CO2 sequestration. In this study, Life cycle assessment (LCA) is applied to quantify the advantages and disadvantages of the transition between extensive and intensive production. The methodology presents a holistic analysis of the several impact categories and amounts of relevant products, services, and resource emissions along their life cycles. In order to assess the environmental effects of the lamb meat production, three sheep breeding systems in Turkey are evaluated. The study aims to promote a sustainable use of natural resources/assets without compromising the quality, competitiveness, or animal welfare and obtain recommendations for the future husbandry systems and rural development in Turkey. As an overall result, it can be stated that the intensification of sheep farming can lead to a decrease of greenhouse gas emissions per kg of meat. However, extensive sheep farming shows less impacts on soil acidification or eutrophication and can even be beneficial for erosion resistance or biodiversity if properly managed.

Exposure to industrial hog operations and gastrointestinal illness in North Carolina, USA

With 9 million hogs, North Carolina (NC) is the second leading hog producer in the United States. Most hogs are housed at concentrated animal feeding operations (CAFOs), where millions of tons of hog waste can pollute air and water with fecal pathogens that can cause diarrhea, vomiting, and/or nausea (known as acute gastrointestinal illness (AGI)). We used NC's ZIP code-level emergency department (ED) data to calculate rates of AGI ED visits (2016-2019) and swine permit data to estimate hog exposure. Case exposure was estimated as the inverse distances from each hog CAFO to census block centroids, weighting with Gaussian decay and by manure amount per CAFO, then aggregated to ZIP code using population weights. We compared ZIP codes in the upper quartile of hog exposure ("high hog exposed") to those without hog exposure. Using inverse probability of treatment weighting, we created a control with similar demographics to the high hog exposed population and calculated rate ratios using quasi-Poisson models. We examined effect measure modification of rurality and race using adjusted models. In high hog exposed areas compared to areas without hog exposure, we observed a 11% increase (95% CI: 1.06, 1.17) in AGI rate and 21% increase specifically in rural areas (95% CI: 0.98, 1.43). When restricted to rural areas, we found an increased AGI rate among American Indian (RR = 4.29, 95% CI: 3.69, 4.88) and Black (RR = 1.45, 95% CI: 0.98, 1.91) residents. The association was stronger during the week after heavy rain (RR = 1.41, 95% CI: 1.19, 1.62) and in areas with both poultry and swine CAFOs (RR = 1.52, 95% CI: 1.48, 1.57). Residing near CAFOs may increase rates of AGI ED visits. Hog CAFOs are disproportionally built near rural Black and American Indian communities in NC and are associated with increased AGI most strongly in these populations.

Profiling the antibiotic resistome in soils between pristine and human-affected sites on the Tibetan Plateau

With increasing pressure from anthropogenic activity in pristine environments, the comprehensive profiling of antibiotic resistance genes (ARGs) is essential to evaluate the potential risks from human-induced antibiotic resistance in these under-studied places. Here, we characterized the microbial resistome in relatively pristine soil samples collected from four distinct habitats on the Tibetan Plateau, using a Smart chip based high-throughput qPCR approach. We compared these to soils from the same habitats that had been subjected to various anthropogenic activities, including residential sewage discharge, animal farming, atmospheric deposition, and tourism activity. Compared to pristine samples, an average of 23.7% more ARGs were detected in the human-affected soils, and the ARGs enriched in these soils mainly encoded resistances to aminoglycoside and beta-lactam. Of the four habitats studied, soils subjected to animal farming showed the highest risks of ARG enrichment and dissemination. As shown, the number of ARGs enriched (a total of 42), their fold changes (17.6 fold on average), and the co-occurrence complexity between ARGs and mobile genetic elements were all the highest in fecal-polluted soils. As well as antibiotics themselves, heavy metals also influenced ARG distributional patterns in Tibetan environments. However, compared to urban areas, the Tibetan Plateau had a low potential for ARG selection and exhibited low carriage of ARGs by mobile genetic elements, even in environments impacted by humans, suggesting that these ARGs have a limited capacity to disseminate. The present study examined the effects of multiple anthropogenic activities on the soil resistomes in relatively pristine environments.

An analysis on determinants of farmers' willingness for resource utilization of livestock manure

The increased manure produced in animal husbandry, especially in beef cattle farming, pose a great threat to the environment. Resource utilization of the manure is an effective way to solve the problem and is conducive to the sustainable development of animal husbandry. Based on the theory of planned behavior, this paper attempts to construct a model of farmers' willingness to utilize livestock manure from behavioral attitude, subjective norm and cognitive behavioral control, and makes an empirical test through a questionnaire on beef cattle farmers. As the findings show, farmers' behavioral attitude, subjective norm and cognitive behavioral control have a significantly positive impact on the resource utilization of the manure. Among them, behavioral attitude exerts the greatest impact, followed by cognitive behavioral control and subjective norm. Farmers surveyed share almost the same attitude towards the effects of resource utilization, who may actively or passively take into consideration the corresponding economic, social and ecological benefits. The pressure from the government plays an important role in farmers' subjective norm, while less pressure comes from village cadres and neighbors. Finally, time or labor endowment and economic strength are the core constraints on the resource utilization of livestock manure by farmers, with relatively little constraint on skill acquisition.

No apparent transmission of livestock-associated methicillin-resistant Staphylococcus aureus CC398 in a survey of staff at a regional Danish hospital

Background

In recent years, livestock-associated methicillin-resistant Staphylococcus aureus (LA-MRSA) multi locus sequence type CC398 has spread widely in the livestock production in Europe. The rates of LA-MRSA in hospitals have been found to be largely determined by contact to and density of livestock in the area.

Methods

This is a cross sectional study of the prevalence of LA-MRSA among hospital staff in a Danish hospital situated in a livestock production region. We analysed nasal swabs, air and dust samples for the presence of MRSA using PCR and mass spectrometry.

Results

Of 1745 employees, 545 (31%) contributed nasal swabs. MRSA was not detected in any participant, nor was it detected in air or dust at the hospital or in houses of employees living on farms. Four percent of the participants had contact to pigs either directly or through household members. LA-MRSA was detected in two of 26 samples from animal sheds, both of them from pig farms. The participation rate was relatively low, but participants were representative for the source population with regards to animal contact and job titles.

Conclusions

The study suggests a low point prevalence of LA-MRSA carriage in Danish hospital staff even in regions where livestock production is dense. Should more studies confirm our findings we see no need for additional hospital precautions towards LA-MRSA in Denmark at the moment. We think that our data might reduce potential stigmatization of hospital workers with contact to LA-MRSA positive farms at their work places and in their communities.

Electronic supplementary material

The online version of this article (10.1186/s13756-017-0284-y) contains supplementary material, which is available to authorized users.

Taxing Meat: Taking Responsibility for One's Contribution to Antibiotic Resistance

Antibiotic use in animal farming is one of the main drivers of antibiotic resistance both in animals and in humans. In this paper we propose that one feasible and fair way to address this problem is to tax animal products obtained with the use of antibiotics. We argue that such tax is supported both by (a) deontological arguments, which are based on the duty individuals have to compensate society for the antibiotic resistance to which they are contributing through consumption of animal products obtained with the use of antibiotics; and (b) a cost-benefit analysis of taxing such animal products and of using revenue from the tax to fund alternatives to use of antibiotics in animal farming. Finally, we argue that such a tax would be fair because individuals who consume animal products obtained with the use of antibiotics can be held morally responsible, i.e. blameworthy, for their contribution to antibiotic resistance, in spite of the fact that each individual contribution is imperceptible.