Jan 01, 2016 · Ma A, Shi W, Niu X, Wang M and Zhong X 2009. Effects of Echinacea purpurea extract on the immunological response to infectious bursal disease vaccine in broilers. Frontiers of Agriculture in China 3, 452–456. Maass N, Bauer J, Paulicks BR, Böhmer BM and Roth-Maier DA 2005. Ef.ciency of Echinacea purpurea on performance and immune status in pigs.