Veterinary medicines and feed additives in the environment following use in the poultry industry

兽药是现代农业实践的支柱，广泛用于治疗疾病和保护动物健康。然而，这些化学品在使用后可能会无意中被引入环境，对生态系统和人类健康构成风险。抗生素等兽药是具有生物活性的化学品，旨在引起影响，当这些化学品进入环境时，这种效力不会丧失。例如，对家禽和家畜施用的抗生素，沿着饲料添加剂，可以通过直接释放到动物废物中而进入土壤系统。因此，在任何新药上市之前，都必须经过一个涉及环境风险评估的授权程序。环境风险评估考虑了化学品的可能接触途径、环境归宿和行为。然而，迄今为止，大多数评价兽药降解的研究都集中在液体粪便上，兽药在家禽粪便中的命运在很大程度上仍然未知。关于给牲畜使用的饲料添加剂的命运，也存在着重大的知识差距。家禽业继续增长，集约化生产单位的发展对环境构成威胁。家禽粪便是非常不同的基质液体粪便具有较低的水含量，通常是有氧的。这种性质的差异有可能改变粪肥本身中化学品的命运和行为，并最终改变这些化学品进入环境时的风险。该项目将通过对兽药和饲料添加剂降解特性的可变性和影响产生新的理解来解决这一重大的知识差距。与Fera Science Limited的科学家合作，将使他们能够获得最先进的仪器、实验室和环境风险评估方面的专业知识。该项目的一个关键方面将建立在以前的研究结果的基础上，这些研究结果表明抗生素可以影响土壤微生物群落的组成和结构，以了解含有抗生素残留物的粪肥如何通过改变酶活性和代谢不同碳源的能力来影响土壤微生物，以及通过改变整体微生物生物量和不同群体的相对丰度。鉴于有机肥料在农业中的使用越来越多以及对兽药的需求，这一主题迫切需要进一步研究。本项目的总体目标是更好地了解兽药在粪便-土壤系统中的归宿和影响。这将通过实验室实验方法和田间试验相结合来实现，田间试验利用了利兹大学农场和Fera Science Limited的设施。具体目标是：1.家禽粪便中兽药和饲料添加剂的降解特性2.更好地了解粪便类型对降解的可变性和性质影响3。研究不同类型有机肥对土壤-植物相互作用的影响，包括对土壤微生物生物量和不同类群土壤微生物相对丰度的影响.评估粪肥和/或土壤样品中相关的抗菌素耐药性（AMR）细菌或基因。这可能是由;分离分类群或感兴趣的分类群，然后进行表型筛选或全基因组测序;靶AMR基因的qPCR，或样品的非靶向高重复序列测序。

Veterinary medicines are a mainstay of modern farming practice and are widely used to treat disease and to protect the health of animals. However, following their use these chemicals can be inadvertently introduced into the environment where they present an ecosystem and human health risk. Veterinary medicines such as antibiotics are biologically active chemicals designed to elicit effects and this potency is not lost when these chemicals enter the environment. Antibiotics administered to poultry and livestock for example, along with feed additives, can make their way in soil systems by direct release in animal waste products. Therefore, before any new medicine can be brought to market it has to undergo an authorisation process which involves an environmental risk assessment. Environmental risk assessments consider the likely exposure routes, environmental fate and behaviour of the chemical. Nevertheless, most research to date evaluating veterinary medicine degradation has focussed on liquid manures and the fate of veterinary medicines in poultry litter remains largely unknown. There is also a significant knowledge gap surrounding the fate of feed additives administered to livestock. The poultry industry continues to grow and the development of intensive production units represents a threat to the environment. Poultry manure is very different matrix to liquid manures with a lower water content and is typically aerobic. Differences in properties such as this have the potential to alter the fate and behaviour of chemicals in the manure itself and ultimately the risk of these chemicals when they are introduced into the environment. This project will address this significant knowledge gap by generating new understanding around the variability and influence of properties on the degradation of veterinary medicines and feed additives. Working in collaboration with scientists at Fera Science Limited will enable access to state-of-the-art instrumentation, laboratories and specialist expertise in environmental risk assessment. A key aspect of this project will build on previous findings which have demonstrated that antibiotics can affect soil microbial community composition and structure to understand how manure laced with antibiotic residues can influence soil microorganisms by changing their enzyme activity and ability to metabolize different carbon sources, as well as by altering the overall microbial biomass and the relative abundance of different groups. This topic urgently warrants further investigation given the increasing use of organic fertilisers in agriculture and the demand of veterinary medicines. Aim and objectivesThe overall aim of this project is to better understand the fate and effects of veterinary medicines in manure-soil systems. This will be achieved using a combination of an experimental approach in the laboratory and field trials utilising facilities available at the University of Leeds farm and Fera Science Limited. The specific objectives are to:1. Characterise the degradation of veterinary medicines and feed additives in poultry manure 2. Develop better understanding of the variability and property influence of manure type on degradation3. Investigate the impact of different manure types of soil-plant interactions including impacts on soil microbial biomass and the relative abundance of different groups soil microorganisms.4. Assess manure and/or soil samples for associated Antimicrobial Resistant (AMR) Bacteria or genes. This could be by; isolation of taxa or interest followed by phenotypic screening or Whole Genome Sequencing; qPCR of target AMR genes, or non-targeted High Throughput Sequencing of samples.