Berry fruits contain vitamins (C, E, folic acid) and other biologically active substances such as tannins, saponins, flavonoids, phenolic acids… that may be beneficial for ruminants. These substances can potentially stimulate the microbial metabolism in the rumen and improve fermentation of nutrients. Berry fruits are processed to produce value-added products such as juices, jams, and jellies, and during this industrial process large amounts of co-products are produced and used for composting, combustion or animal feeds.
Polish researchers evaluated the effects of black current seed residues obtained from a fruit juice processing plant on milk production performance of dairy cows. After separation from dried pomace, the seeds were crushed, and oil was extracted using supercritical carbon dioxide as a solvent. The black current seed residues contained 26.2% protein in a dry matter basis (DM) and 30.4% crude fiber. Fat concentration was 5.8% with linoleic and linolenic acids being the major fatty acids (45.9 and 27.2% of fatty acids, respectively). In addition, the residue was rich in flavonoids (18.3 mg/100 g) and anthocyanins (37.6 mg/100 g).