Written by: Dr. Jacquie Jacob, University of Kentucky
Potato protein is a by-product of the production of potato starch. Potato starch is more common in Europe, where it is used in applications that in the United States would call for corn starch.
The effects of including potato protein in poultry diets are varied. Research has shown that inclusion of potato protein in broiler diets can result in an increased incidence of subclinical necrotic enteritis. It is speculated that this increase is due to the presence of antinutritional factors in potato protein, such as high trypsin-inhibitor activity and low lipid content. Research has also shown that feeding potato protein to poultry has an antimicrobial effect in the intestines, reducing the level of coliforms, useful E. coli–like bacteria that serve as indicators of fecal contamination. In contrast, other research has suggested that potato protein can be used as an alternative to antibiotics in poultry diets. The differing outcomes may be related to the types of potatoes used in the production of the potato proteins.
Because there are no sources of organic potato protein, potato protein cannot be used in organic diets in the United States, Canada, or Europe. (In the past, restricted amounts of nonorganic materials were allowed in poultry diets in Europe, so organic diets could include a limited amount of potato protein as a substitute for synthetic methionine.)