Protein extracted from green biomass can be a sustainable and valuable feed component for organic poultry production. Earlier studies in rats have shown high digestibility of laboratory‐scale extracted protein. The aim of this study was to test the effect of upscaling the biorefining process on composition of protein extracted from organic grass‐clover and on performance of organic broilers when including grass‐clover in the feed. Crude protein content of the extracted grass‐clover protein was 36.2% of dry matter (DM) with a higher methionine content, but lower lysine and total sulphur‐containing amino acids than that in soybean. Acid‐insoluble residue constituted a major fraction of the dietary fibre content, and a large proportion of total CP was bound in this fraction. Alpha‐linolenic acid was the dominating fatty acid in the extracted grass‐clover protein. One‐day‐old organic Colour Yield broiler chicks were included in a dose–response trial with grass‐clover protein constituting 0%, 8%, 16% or 24% of the feed from day 12 and until slaughter at day 57. Increasing levels of grass‐clover protein extract reduced feed intake, growth and slaughter weight; however, at 8% inclusion feed intake and performance were not affected. The fatty acid composition in broiler breast meat reflected the composition of grass‐clover protein extract; thus, the increasing dietary addition increased meat alpha‐linolenic acid content. A lowered tocopherol content in meat from broilers fed increasing grass‐clover protein demonstrated the need for increased amounts of antioxidants due to the high content of unsaturated fat. In conclusion, the study shows that broilers can grow on grass‐clover protein from an upscaled biorefining process, but highlights the importance of further optimisation with focus on increased protein content and on avoiding formation of insoluble protein complexes, as these most likely reduce protein digestibility.

中文翻译：

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生物精制的三叶草蛋白质组成及其对有机肉鸡生产性能和肉脂肪酸组成的影响。

从绿色生物质中提取的蛋白质可以成为有机家禽生产的可持续且有价值的饲料成分。早期的大鼠研究表明，实验室规模提取的蛋白质具有高消化率。本研究的目的是测试升级生物精炼工艺对从有机草三叶草中提取的蛋白质成分的影响，以及在饲料中加入草三叶草时对有机肉鸡生产性能的影响。提取的草三叶草蛋白质的粗蛋白质含量为干物质 (DM) 的 36.2%，蛋氨酸含量较高，但赖氨酸和总含硫氨基酸含量低于大豆。酸不溶性残留物构成膳食纤维含量的主要部分，并且总 CP 的很大一部分结合在该部分中。α-亚麻酸是提取的草三叶草蛋白中的主要脂肪酸。从第 12 天到第 57 天屠宰，一天大的有机颜色产量肉鸡被纳入剂量反应试验，草三叶草蛋白占饲料的 0%、8%、16% 或 24%。草三叶草蛋白提取物降低了采食量、生长和屠宰重量；然而，在 8% 的含量下，饲料摄入量和性能没有受到影响。肉鸡胸肉的脂肪酸组成反映了草三叶草蛋白提取物的组成；因此，增加膳食添加量会增加肉类 α-亚麻酸的含量。饲喂增加草三叶草蛋白的肉鸡的肉中生育酚含量降低表明，由于不饱和脂肪含量高，需要增加抗氧化剂的量。综上所述，