Feed conversion ratio (FCR) in grow-finishing pigs is one of the most important determinants of pig farm profitability and production efficiency. In its simplest form, FCR represents the amount of feed used per unit weight gain of the pig. Yet, this approach entails various limitations hampering its practical applicability such as availability of accurate data and large variation in ways to adapt FCR values for different starting and end weight as well as mortality rates. Various stakeholders are using their own formulas to determine FCR creating a ‘definition nonconformity’ when comparing FCRs among farms. This study aimed to optimize the calculation of FCR through the use of participatory qualitative research. A multidisciplinary research group of 9 persons (animal scientists, veterinarians and agricultural economists) and a consulting group of 31 stakeholders (representing the Flemish primary sector, feed industry, pharma, genetic companies, large retailers, academia and policy institutions) were involved. The decision problem analysis started with a literature review, followed by 25 in-depth interviews and their analyses (NVivo 11™). This led to an additional literature review and the formation of focus (expert) groups that helped to formulate preliminary FCR formulas. Revision rounds between the research team and the stakeholders further fine-tuned the formulas with the final result being two distinct complimentary formulas that are fit for purpose. Both refer to carcass gain per kg feed intake (plain (CGF) and standardized (CGFstandardized)). The first formula (CGF), namely ${{{\it{number \, delivered \, pigs}} \times {\it{average \, warm \, carcass \, weight}} - {\it{number \, stocked \, piglets}} \times {\it{average \, piglet \, weight}} \times {\it{piglet \, carcass \, yield}}} \over {{\it{feed \, consumption}}}}$ is an objective representation of the animals’ performance. The second formula (CGFstandardized) was developed for farm benchmarking, incorporating a seven-step standardization process that corrects for mortality and ‘standardizes’ for a fixed (yet fictive) live weight trajectory of 25 to 115 kg. This second formula allows to compare farms (or batches of fattening pigs) with different weight trajectories and different mortality rates. A webtool was designed to ease this standardization process (https://varkensloket.be/tools/CGF).

饲料转化率（FCR生长肥育猪）是决定猪场盈利能力和生产效率的最重要因素之一。FCR以其最简单的形式表示每单位猪体重增加所使用的饲料量。然而，这种方法存在各种限制其实用性的局限性，例如精确数据的可用性以及在使FCR值适应不同起始重量和最终重量以及死亡率的方式上存在较大差异。在比较农场之间的FCR时，各种利益相关者正在使用自己的公式来确定FCR，从而造成“定义不合格”。本研究旨在通过参与性定性研究来优化FCR的计算。一个由9人组成的多学科研究小组（动物科学家，兽医和农业经济学家）以及一个由31个利益相关者组成的咨询小组（代表佛兰德第一产业，饲料工业，制药，遗传公司，大型零售商，学术界和政策机构）。决策问题分析首先进行文献综述，然后进行25次深入访谈及其分析（NVivo 11™）。这导致了额外的文献综述并形成了焦点（专家）小组，这些小组帮助制定了初步的FCR公式。研究团队和利益相关者之间的修订轮次进一步调整了公式，最终结果是两个适合目的的独特公式。两者均指每公斤采食量的car体增重（纯（学术界和政策机构）。决策问题分析首先进行文献综述，然后进行25次深入访谈及其分析（NVivo 11™）。这导致了额外的文献综述并形成了焦点（专家）小组，这些小组帮助制定了初步的FCR公式。研究团队和利益相关者之间的修订轮次进一步调整了公式，最终结果是两个适合目的的独特公式。两者均指每公斤采食量的car体增重（纯（学术界和政策机构）。决策问题分析首先进行文献综述，然后进行25次深入访谈及其分析（NVivo 11™）。这导致了额外的文献综述，并形成了有助于制定FCR初步公式的焦点（专家）小组。研究团队和利益相关者之间的修订轮次进一步调整了公式，最终结果是两个适合目的的独特公式。两者均指每公斤采食量的car体增重（纯（研究团队和利益相关者之间的修订轮次进一步调整了公式，最终结果是两个适合目的的独特公式。两者均指每公斤采食量的car体增重（纯（研究团队和利益相关者之间的修订轮次进一步调整了公式，最终结果是两个适合目的的独特公式。两者均指每公斤采食量的car体增重（纯（CGF）和标准化（CGF标准化）。第一个公式（CGF），即 $ {{{\ it {number \，已交付\，猪}} \次{\ it {平均值\，温暖\，cas体\，体重}}-{\ it {number \，放养的\，仔猪}} \次数{\它{平均\，仔猪\，体重}} \次数{\ it {仔猪\，cas体\，产量}}}} \超过{{\ it {饲料\，消耗}} }} 是动物表现的客观表示。第二个公式（CGF标准化 ）是为农场基准测试而开发的，它包含一个七步标准化过程，该过程可校正死亡率并“标准化” 25至115公斤的固定（但仍为假想的）活体重轨迹。第二个公式可以比较体重轨迹和死亡率不同的农场（或成批的育肥猪）。设计了一个网络工具来简化此标准化过程（https://varkensloket.be/tools/CGF）。