WASHINGTON – Vaccinating chicks usually involves an electronic sprayer. But the spray could miss some chicks, leaving them vulnerable to diseases. But what healthy chick misses a meal?

Scientists with the US Department of Agriculture's Agricultural Research Service (ARS) have developed a vaccine that chicks can eat. The vaccine protects the birds against intestinal diseases such as coccidiosis, a common poultry disease caused by tiny, single-celled parasites. Birds infected with the parasites are slow to gain weight and grow, and sometime they die.

The alternate vaccine delivery system involves putting low doses of live Eimeria oocysts inside gelatin beads, which are fed to birds. The alternate vaccine was developed by scientists at the ARS Henry A. Wallace Beltsville Agricultural Research Center (BARC) in Beltsville, Md., and Southwest Research Institute (SwRI) in San Antonio, Texas.

In laboratory experiments, one-day-old chicks were immunized by eating the gelatin beads or with a hand-held sprayer. Microbiologists found that the chicks that ate gelatin beads had a greater vaccine uptake than the group that was vaccinated via electronic sprayer. Microbiologist Mark Jenkins and zoologist Ray Fetterer, in BARC's Animal Parasitic Diseases Laboratory, conducted the tests using chicks of layer hens and broilers.

Researchers also found that chicks fed gelatin beads had greater weight gains compared to unvaccinated chicks, and were more capable of converting feed into body mass.

ARS and SwRI scientists have filed a patent application for this research and are working on a gelatin bead vaccine for commercial poultry houses.