Decision-making environment of low-protein animal feeding in dairy and poultry farms in China

Low-protein feeding is a strategy used to decrease nitrogen excretion and ammonia (NH3) emissions from animal manure, while maintaining productivity. The optimal protein content depends on many factors, including the type, age, and production level of the animal, as well as the availability, composition, and digestibility of the feed ingredients. Farmers in many developing countries lack information about the protein content of feed and about low-protein feeding, including those in China. This lack of information hinders the making of accurate NH3 emission inventories and strategies for reducing these emissions. We determined farmers’ knowledge and perceptions of low-protein feeding in 338 livestock farms, and the actual protein content of 591 feed samples collected from China. Farmers knew little about protein and low-protein feeding; they simply followed the instructions from feed-delivering companies or contracting companies. The mean protein content of the dairy cows’ diets (159 ± 20 g/kg DM) was relatively low. Layer hens’ diets had a mean protein content of 184 ± 22 g/kg DM, and 14% of their diets were in excess of requirement. Broiler farms used compound feed, of which 23% were in excess of requirement and 15% were deficient in protein. Overall, the mean protein contents were close to the recommended levels for low-protein animal feeding, according to national guidelines, which are similar to the guidelines of the National Research Council (NRC) of the United States. However, there were large variations between farms, suggesting the scope for improvement on many farms. Our research provides farmers, feed companies, policy makers, and institutions with useful information to improve feed management, and to improve the inventories and assessment of NH3 emissions from animal production.