Researchers found that at least 70 distinct byproduct feeds are used on California dairy farms. In total, California dairies included about 5.5 million tons of byproduct feeds in their lactating and dry cow rations. With a ration share of approximately 38% of feed on California dairies, byproducts were found to be the largest feed category by cost and dry matter share.
The inclusion of byproducts in dairy rations allows a productive outlet for many materials that may otherwise be sent into the waste stream. If dairies did not use byproducts for feeds, much more land and water resources would need to be dedicated to dairy feed production. For example, if no byproducts were available, rations would need to include additional amounts of feed options like alfalfa hay and corn grain.