WASHINGTON – The use of antimicrobial proteins that kill pathogens in chickens is one alternative to using antibiotics to control infectious diseases in poultry, according to the US Department of Agriculture’s Agricultural Research Service (ARS).

Hyun Lillehoj, a molecular biologist with USDA’s Agricultural Research Service, and her colleagues have identified an immune molecule called NK lysine, a host antimicrobial protein that can kill pathogens, improve immune response and promote growth of beneficial gut bacteria in poultry, according to ARS. Lillehoj and her colleagues demonstrated for the first time that NK lysine kills chicken coccidia. Poultry diseases such as coccidiosis cause poultry losses of more than $600 million in the US and $3.2 billion worldwide, ARS said.

The protein is also effective against other pathogens such as Neospora and Crytposporidia, which affect livestock and humans, respectively.

Lillehoj is researching other alternatives to antibiotic use in poultry, including phytochemicals from peppers, plums, safflower, green tea and other plants. Phytochemicals have been shown to be effective in enhancing the immune system of chickens, according to ARS. Probiotics are also an alternative because they promote health and balance in the intestinal tract.