WASHINGTON — Agricultural Research Service immunologist Hyun Lillehoj has been working with colleagues in A.R.S. and around the world to find dietary supplements that strengthen the poultry immune system against the parasite Eimeria maxima, which can develop into a disease estimated to cost producers globally more than $1.2 billion a year, according to a report published in the latest issue of the agency’s Agricultural Research magazine.
Chickens that consumed ground green tea for two weeks before parasitic infection produced significantly fewer fecal E. maxima oocysts than the control group, the researchers found. This could help reduce the spread of infection in poultry houses.
The effects of adding commercial probiotics, health-promoting dietary supplements derived from live bacteria or yeasts, to poultry diets were also evaluated.
Researchers determined chickens eating diets supplemented with Pediococcus-based probiotics reduced their oocyte production, increased the production of cytokines essential for a strong immune response and experienced improved weight gain.
A combination of Pediococcus and a yeast-based commercial probiotic product gave poultry immunities a similar boost, Ms. Perry writes. Chickens consuming a probiotic combination of lactic-acid bacterium and yeasts also showed a significant antibody response to parasites.
Investigators also wanted to learn if other phytonutrients might be beneficial. They discovered plum-powder supplements stimulated spleen immune cell production and killed tumor cells. Infected poultry fed with the supplement also gained weight and reduced parasite shedding. Supplements of safflower, which have been used by traditional Chinese practitioners for thousands of years, were found to be similarly beneficial.