Preventing drops in egg production in UK free-range flocks: understanding the interactions between farm practices, flock coinfections and immunity

防止英国散养鸡群产蛋量下降：了解农场实践、鸡群共感染和免疫之间的相互作用

• 批准号: BB/X017591/1
• 负责人: KANNAN Ganapathy
• 金额: $ 78.47万
• 依托单位: University of Liverpool
• 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%2FX017591%2F1
• 关键词: Preventing; drops; egg; production; UK

The demand for poultry eggs and meat is increasing globally. The poultry industry contributes £4.6 billion per year to the UK economy. The UK produces more than 10 billion table eggs a year, 65% of which comes from free-range farms. Currently, no data is available on the total number of eggs lost in the free-range farms. However, based on a study by Scottish Rural College (SRU), it is estimated that egg losses amount to approximately 6-25% per flock, which totals to no less than 30-130 million eggs a year.To date, there have been no retrospective studies on health and production of free-range flocks in UK, or on the influence of various routine farm practices on birds' health and production. In fact, in recent years, a new strain of hybrid hens (eg. HyLine) has been introduced to egg farming. These hens stay on egg production for over 100 weeks of age, instead of the conventional 72-80 weeks, but the pre-lay vaccination programme remains the same. There has also been much variations in in-lay health management such as type, frequency and duration of deworming, mite control, antibiotics usages, and in-lay vaccination farm activities. A notable observation by field veterinarians is that at present, there is no information on coinfection or waning immunity of free-range egg laying flocks on the drops in egg production and quality. Coinfection by one or more of the following pathogens have been strongly implicated with egg losses; i) infectious bronchitis virus (IBV), ii) avian metapneumovirus (aMPV), iii) Mycoplasma gallisepticum (Mg), Mycoplasma synoviae (Ms) and iv) Ornithobacterium rhinotracheale (ORT), and v) infectious laryngotracheitis (ILT), but to date, there is little or no scientific evidence. This proposed study, for the first time in the UK, investigates two main variables; coinfection and immunity levels of flocks from 16 weeks to culling ages of the birds. Flock health and production will be assessed concurrently to appreciate statistical association between these variables.Results from the proposed project will establish a link between egg production pattern, immune status of flocks, influence of farm practices, and the role of single or coinfections. Science-based evidence from this study will be used to demonstrate the following, i) the normal and abnormal egg production patterns in free-range flocks in UK, ii) the association between various routine farm practices such as parasite control, vaccinal immunity, antibiotics usages on egg production pattern, iii) a list of common causes of EPQ drops, d) ways to strengthen the pre-lay and in-lay vaccination in order to sustain higher and prolonged immunity in flocks. The research outputs of this project would benefit the UK and global farming industry.

全球对禽蛋和禽肉的需求正在增加。家禽业每年为英国经济贡献46亿英镑。英国每年生产超过100亿个食用鸡蛋，其中65%来自自由放养农场。目前，没有关于自由放养农场损失鸡蛋总数的数据。然而，根据苏格兰农村学院（SRU）的一项研究，估计每只鸡的鸡蛋损失约为6-25%，每年损失的鸡蛋总数不少于3000 - 1.3亿个。迄今为止，还没有关于英国自由放养鸡群的健康和生产的回顾性研究，也没有关于各种常规农场做法对鸟类健康和生产的影响的回顾性研究。事实上，近年来，一种新型杂交母鸡(如：HyLine)已被引入鸡蛋养殖。这些母鸡的产蛋时间超过100周龄，而不是传统的72-80周龄，但产前疫苗接种计划保持不变。在圈层健康管理方面也存在很大差异，如驱虫的类型、频率和持续时间、螨虫控制、抗生素使用和圈层疫苗接种农场活动。现场兽医观察到的一个值得注意的现象是，目前没有关于放养产蛋禽的共同感染或免疫力下降导致蛋产量和质量下降的信息。以下一种或多种病原体的共同感染与卵子损失密切相关；i)传染性支气管炎病毒（IBV）， ii)禽中性肺病毒（aMPV）， iii)鸡脓毒支原体（Mg），滑膜支原体（Ms）和iv)鼻气管鸟杆菌（ORT）， v)传染性喉气管炎（ILT），但迄今为止，很少或没有科学证据。这项在英国首次提出的研究调查了两个主要变量；禽群从16周龄至扑杀年龄的共感染和免疫水平。将同时评估畜群健康和生产，以了解这些变量之间的统计关联。拟议项目的结果将确定产蛋模式、鸡群免疫状况、农场做法的影响以及单一或共同感染的作用之间的联系。来自本研究的基于科学的证据将用于证明以下几点：1)英国自由放养鸡的正常和异常产蛋模式；2)各种常规农场做法（如寄生虫控制、疫苗免疫、抗生素使用对产蛋模式的影响）之间的联系；3)EPQ下降的常见原因清单；4)加强产蛋前和产蛋内疫苗接种的方法，以维持鸡群更高和更长时间的免疫力。该项目的研究成果将有利于英国和全球农业。