Grass-clover protein can partly substitute traditional feed protein for broilers

According to a new study from Aarhus University, protein produced by biorefining of grass-clover can replace at least 13 % of the traditional feed protein used for organic broilers without compromising production parameters

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

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

Fiber digestibility and protein value of pulp silage for lactating dairy cows: Effects of wet fractionation by screw pressing of perennial ryegrass

ABSTRACT: The aim of the study was to investigate the effects of substituting silage of chopped grass with pulp silage of grass fractionated once or twice in a biorefinery using a screw press on fiber kinetics, protein value, and production of CH4 in dairy cows. Six lactating multiparous Holstein cows in mid-lactation (176 ± 93 d in milk), cannulated in the rumen, duodenum, and ileum, were used in an incomplete 6 × 4 Latin square design with a 2 × 3 factorial arrangement of treatments. Perennial ryegrass was harvested in third regrowth from the same field at early and late developmental stage (35 and 44 d of regrowth, respectively) and subjected to 1 of 3 types of processing within each developmental stage. Grass was either harvested for normal silage making (mowed, wilted, chopped, and ensiled), or harvested fresh and fractionated using a screw press. Half of the pulp from the first fractionation was ensiled, whereas the other half of the pulp was rehydrated, fractionated a second time, and pulp hereof was ensiled. The grass and pulp silages were used with concentrates (65:35 forage to concentrate ratio) to make total mixed rations (TMR) based on either silage of chopped grass (GS), pulp silage of grass fractionated once (1×P), or pulp silage of grass fractionated twice (2×P), harvested either at early (E) or late (L) developmental stage resulting in 6 different TMR treatments (EGS, E1×P, E2×P, LGS, L1×P, L2×P). The TMR were fed for ad libitum intake and samples of intestinal digesta and feces were collected for determination of digestibility. The effect of processing on ash-free neutral detergent fiber (aNDFom) concentration in silages depended on developmental stage, but showed that within each developmental stage, pulp silage of grass fractionated twice had higher aNDFom concentration than pulp silage of grass fractionated once and silage of chopped grass. The 2×P resulted in lower (14.9 ± 0.55 vs. 17.5 ± 0.54 kg/d) dry matter intake (DMI) compared with GS. The effects of processing and developmental stage interacted such that apparent total-tract aNDFom digestibility was higher (784 ± 13 vs. 715 ± 13 g/kg) for L2×P compared with LGS, whereas no difference was found between E2×P and EGS. Moreover, the protein value was higher (106 ± 5 vs. 92 ± 5 g AA digested in the small intestine/kg of DMI) for 2×P compared with GS. Unexpectedly, processing had no effect on fractional rate of digestion of digestible aNDFom or CH4 yield (L/kg of DMI), whereas feeding forages harvested at early compared with late developmental stage resulted in lower CH4 yield. Feeding pulp silage of grass fractionated once generally yielded results intermediate to cows fed silage of chopped grass and pulp silage of grass fractionated twice. This study showed that pulp silage of fractionated grass could serve as feed for dairy cows because the fiber digestibility and protein value improved, but further research investigating effects of physical processing of forage on fiber kinetics is required