June 1, 2012
Alternative methods to treat poultry diseases without antibiotics
A method being used by US Department of Agriculture (USDA) scientists to control infectious poultry diseases besides using antibiotics is by identifying antimicrobial proteins in chickens that kill pathogens.
Each year,
poultry diseases such as coccidiosis cause losses of more than US$600 million in the United States and US$3.2 billion worldwide.
Molecular biologist Hyun Lillehoj, at the Agricultural Research Service (ARS), the
USDA''s chief intramural scientific research agency, has been studying methods to produce poultry without using drugs. Her research includes enhancing innate immunity through genetics, and examining molecules produced by birds in response to enteric or intestinal pathogens.
According to Lillehoj, some molecules are host antimicrobial proteins that can kill pathogens, improve immune responses and promote the growth of beneficial gut bacterial populations in poultry. She and her colleagues have identified one such immune molecule, called NK lysin.
It is demonstrated for the first time that NK
lysine kills chicken coccidia. This antimicrobial protein or host defense molecule is effective against other parasites such as Neospora and Cryptosporidia, which infect
livestock and humans, respectively. One commercial company is looking at the possibility of developing NK lysin into a product that can be used to kill chicken intestinal parasites.
In addition, Lillehoj studies enteric bacterial infections caused by Clostridium, a pathogen associated with necrotic enteritis in poultry. She is using a similar molecular technology to develop alternatives to treat this disease.
Working with industry, international partners and other scientists, Lillehoj has discovered other options to antibiotic use in poultry. Phytochemicals derived from peppers, plums, safflower, green tea and other plants have been shown to be effective in enhancing the immune system of chickens. Furthermore, the beneficial effects of probiotics, which are live, nonpathogenic bacteria that promote health and balance of the intestinal tract microbiota, have been demonstrated in past research.