As more ethanol plants are built, livestock farmers will be forced to feed distillers grains (DGs) as this by-product will, in many cases, be cheaper than maize, according to Dr Tom Tylutki of US-based Agricultural Model Systems.
However, he warned delegates at the recent annual symposium of the Associated Feed Manufacturers’ Association that few ­quality control measures are in place for DGs, which are the residue left after the fermentation and distilling process.
Due to their poor amino acid pattern, a relatively high phosphorus content, and a high degree of variation, DGs are a very challenging ingredient to use efficiently, even though they have been used as feed for more than 100 years in North America where they originated from the beverage industry. Where large amounts of by-products are fed, total fat and unsaturated fatty acid levels must be watched or else milk fat depression will occur. The risk of depressed animal performance is high and DG inclusion rates should be limited to less than 10%; Tylutki said. – Roelof Bezuidenhout