Echinacea purpurea as a potential immunostimulatory feed additive in laying hens and fattening pigs by intermittent application

The aim of the present trial was to evaluate the effect of repeated short-time applications of Echinacea purpurea juice as feed additive to initiate an immune response. In a trial with 70 white layers (LSL) two Echinacea juices as feed additives were tested for their influence on feed intake, performance, blood cell counts. phagocytosis of granulocytes, and antibody titer against Newcastle Disease Virus (NDV) following vaccination. Echinacea juice was pressed juice of aerial parts of the plant preserved with either ethanol (20%) or by fermentation. The application scheme followed a repeated 14 days regimen with either 5 days of application and 9 days without or 2 days of application and 12 days without. Blood was taken several times following an application period. The performance of the hens was not impacted. Significant changes were found in the number of lymphocytes (p<0.002), phagocytosis rate (p<0.02), and NDV antibody titer (p<0.01). The number of lymphocytes was highest in the group receiving ethanolic juice for five consecutive days. Phagocytosis was reduced in both groups provided with ethanolic juice (2 or 5 days). Highest NDV antibody titers were seen in the groups receiving fermented juice for 2 days. Additionally, phagocytosis of granulocytes was determined in fattening pigs (80 - 100 kg) after 5 days of Echinacea application with ethanolic or fermented juice. A significant increase (p<0.005) was found with both Echinacea formulations. The number of lymphocytes was also increased significantly in the groups provided with Echinacea (p<0.008). (C) 2008 Elsevier B.V. All rights reserved.