Clover-grass protein by bio-refining: nutrient composition and shelf life (OK-Net EcoFeed practice abstract)

Summary in the original language of the document

Green protein can substantially increase the proportion of locally produced protein used in animal feed, reducing imports of soy-based protein sources. Green protein concentrate contains a high protein and amino acid content. Storage of the green protein preserves protein quality and extends its value as a feed source. Anaerobic storage on farm would be much cheaper than drying.
• Protein content of the green protein concentrate was 48.5% DM on the day of harvest and the methionine (10.8g/kg DM) and lysine content (31.4g/kg DM) was optimal for both poultry and pigs.
• Dry matter, ash, protein (Figure 1) and amino acid (Figures 2 and 3) content increased during storage.
• Samples stored at 24°C had high concentrations of butyric acid. Butyric acid-forming bacteria, e.g. clostridia, use lactic acid as a substrate to produce butyric acid (Figure 4). It is crucial that the product maintains a good quality during storage. Concentration of lactic acid bacteria was highest in samples stored at 4 °C (Figure 5).
• Shelf life of fresh green protein concentrate is limited. Under anaerobic conditions, the product is stable at: 24°C for a maximum of 2 months, at 4°C for a maximum of 3 months.
• Temperature was the most significant determinant of shelf life – adding lactic acid bacteria had minimal effect.
• Dried green protein has a dry matter content > 90-95%. The dry matter content of the green protein the day of harvest was 44%. To avoid microbial spoilage during anaerobic storage, reducing the water content during the bio-refining process would be desirable.
• Cooperation with a bio-refinery plant is recommended to produce the clover-grass protein concentrate, for either wet or dry storage.