Intended and unintended consequences of the ZnO ban from pig diets on antimicrobial resistance, post-weaning diarrhoea and the microbiome.

猪日粮中禁用氧化锌对抗菌素耐药性、断奶后腹泻和微生物组的有意和无意的影响。

• 批准号: BB/Y004086/1
• 负责人: Deborah Hoyle
• 金额: $ 73.31万
• 依托单位: University of Edinburgh
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2024
• 资助国家: 英国
• 起止时间: 2024 至 无数据
• 项目状态: 未结题
• 来源: https://gtr.ukri.org/projects?ref=BB%2FY004086%2F1
• 关键词: Intended; unintended; consequences; ZnO; ban

In most countries, farmed pigs are typically weaned at around four weeks of age. Young pigs are especially vulnerable to gut problems due to their immature digestive system and are particularly susceptible to a condition known as post-weaning diarrhoea. Post-weaning diarrhoea results in distress and discomfort in affected animals, and can lead to death. Recovered piglets often have poorer health and reduced growth, affecting welfare and farm productivity. Gastro-intestinal disease is currently the single most significant challenge to the sustainability of UK and global pig systems and affects more than half of pig farmers worldwide, at significant cost to the industry. Until recently, post-weaning diarrhoea was controlled by the addition of Zinc Oxide (ZnO) to feed after weaning, which reduced disease and improved piglet outcomes. However, due to concerns that ZnO contributes to the development of antibiotic resistance, prophylactic use of ZnO has recently been banned in both the EU and UK. At present, there is no direct replacement for ZnO, but rather a range of practices. These include a variety of nutritional and management changes, that may be variously applied according to the circumstances of each farm. This is prompting concern that by withdrawing ZnO, post-weaning diarrhoea may become more difficult to manage, with adverse consequences on piglet health and welfare. Despite the sector's best efforts, treatment will more likely need to rely on antibiotics to treat disease and manage diarrhoea. This, therefore, presents us with a conundrum: banning ZnO may possibly increase antibiotic resistance on farms, because farmers may need to use more antibiotics in practice, to treat sick piglets after weaning. These intended and unintended consequences of ZnO withdrawal are the focus of this proposal.In this study, we will work closely with producers over the withdrawal period to investigate the impact of ZnO withdrawal on piglet health and to identify measures that may help. In particular we are interested in the consequences of ZnO withdrawal on the levels of disease-causing bugs on farms and any changes in carriage of antibiotic resistance by pigs. We will do so by collecting dung samples from a small number of commercial herds across the UK and comparing samples from before and after the ZnO ban. We have already collected pre-ban samples from a number of UK commercial herds, in a precursor pilot project to this proposed study. Laboratory analysis of these dung samples will show which disease-causing bugs are present, and allow us to look for changes in the characteristics of these bugs and their association with disease, before and after the ZnO ban. Using genome sequencing technologies, we will look for antibiotic resistance markers, to see whether these all change after ZnO is withdrawn. Our findings will provide a 'barometer' of piglet health across UK farms during the transitional withdrawal period. We will also examine what differences are seen in the healthy gut microflora in pigs in the presence of ZnO and whether particular beneficial bacteria can be identified. We will investigate how we can exploit these differences to develop alternative feed supplements, such as "friendly bug" supplements that may help in the control of disease and improve piglet health.By providing evidence-based information, this project will help offset existing uncertainties and inform wider discussion as the sector adjusts to 'zero zinc.' This in turn would be expected to lead to the development of pig production systems that deal sustainably with the challenge of managing the post-weaned piglet.

在大多数国家 /地区，养殖猪通常在大约四个星期大的时候断奶。由于其不成熟的消化系统，幼猪特别容易受到肠道问题的影响，并且特别容易受到称为断奶后腹泻的疾病。断奶后的腹泻会导致受影响动物的困扰和不适，并可能导致死亡。恢复的仔猪的健康状况通常较差，生长降低，影响福利和农场生产力。目前，胃肠道疾病是英国和全球猪系统可持续性的最重大挑战，并影响了全球一半以上的养猪场，这对该行业付出了巨大的代价。直到最近，断奶后添加氧化锌（ZnO）在断奶后喂食，从而降低了疾病和改善的仔猪结局，还控制了断奶后的腹泻。但是，由于担心ZNO有助于抗生素耐药性的发展，因此最近在欧盟和英国都禁止了对ZnO的预防性使用。目前，Zno还没有直接替代，而是一系列实践。这些包括各种营养和管理变化，可以根据每个农场的情况进行各种应用。这引起了人们的关注，即通过撤回Zno，断奶后的腹泻可能变得更加困难，对小猪健康和福利产生不利的影响。尽管该部门尽了最大的努力，但治疗更可能需要依靠抗生素来治疗疾病和治疗腹泻。因此，这给我们带来了一个难题：禁止ZnO可能会增加农场的抗生素耐药性，因为农民可能需要在实践中使用更多的抗生素来治疗断奶后的病小猪。 ZNO撤离的这些预期和意外的后果是本提案的重点。在这项研究中，我们将在撤回期间与生产者紧密合作，以调查ZnO撤离对小猪健康的影响并确定可能有所帮助的措施。特别是，我们对ZnO撤离对农场引起疾病的虫子水平的后果以及猪抗生素耐药性的任何变化都感兴趣。我们将通过从英国各地的少量商业群中收集粪便样本，并比较Zno禁令前后的样品。我们已经在这项拟议的研究的前体试点项目中收集了许多英国商业牛群的前式样品。对这些粪便样本的实验室分析将显示存在哪些引起疾病的虫子，并让我们在ZnO禁令前后都在寻找这些虫子的特征及其与疾病的关系的变化。使用基因组测序技术，我们将寻找抗生素耐药性标记，以查看ZNO撤回后是否所有这些变化。在过渡期间，我们的发现将为整个英国农场提供“晴雨表”。我们还将检查在ZnO存在下猪的健康肠道菌群中看到什么差异，以及是否可以鉴定出特定的有益细菌。我们将研究如何利用这些差异来开发替代饲料补充剂，例如“友好的虫子”补充剂，这些补充剂可能有助于控制疾病并改善小猪健康。通过提供基于证据的信息，该项目将有助于抵消现有的不确定性，并随着行业适应“零ZINC”的调整。反过来，这将导致猪生产系统的发展，从而可持续应对处理后猪的挑战。