Valuable Nutritional Ingredients for the Feed Industry
UK maltsters process two million tonnes of the finest British barley every year, producing malt and malt-based food ingredients for use in the food and drink industries around the world.
Resulting from the core process, in addition to malted barley, there are several streams of co-products which maltsters collect, store, and sell on to animal feed compounders or for feeding straight.
The most important of these co-products nutritionally is malt residual pellets, which are based on culms-the rootlets produced by the germinating corns of barley. These culms are high in protein at around 25%. They are separated from the malt after kilning, having no value to a brewer or other user of the malt, and are quite dry at this stage.
Culms are low in bulk density as a loose product, and so are usually pelletised in a blend with other co-product streams.
The other streams suitable for mixing with the culms are small malt corns plus barley dust and malt dust. These are combined for feeding to a pellet mill to produce pellets of bulk density around 600kgm-3 and a protein content around 18%. This is sold as malt residual pellets.
Barley screenings make up the balance of the co-product streams: small barley corns unsuitable for malting are separated prior to processing and sold into the feed market. These will have a slightly higher protein content than the parent bulk of malting barley.
Maltings are certified to the FEMAS standard, and all malting co-products are produced with Good Manufacturing Practice.
It is important to be aware that co-products may have higher mycotoxin levels than the parent bulks of malting barley due to the concentration of husk and outer parts of the corn. This may be particularly of concern for compounding feed for weaner piglets, which are as sensitive to zearalenone as humans.
Another important note of caution specifically for the equine feed industry: the natural storage protein in barley is hordein, which produces hordenine as a metabolite during malting. Hordenine is classified as a Naturally Occurring Prohibited Substance (NOPS) within the FEMAS standard. Malting co-products which contain culms should be avoided when formulating equine feeds.
The availability of a consistent co-product stream of more than 50,000 tonnes throughout the year from maltings across the UK is a valuable resource to the feed sector.