The effects of <i>Echinacea purpurea</i> dried extract on humoral immune response of broiler chicks to Newcastle vaccination

Abstract

Nowadays, using of live and killed vaccines is usually done to prevent Newcastle disease of poultry; however, some of the poultry farms are being encountered with this disease because the available vaccines do not produce enough antibody titers. In this research, an attempt was made to investigate the effect of using an immune stimulator Echinacea purpurea on antibody production against Newcastle vaccine. Four hundred and fifty (450) broiler chicks (Cobb) were divided into five groups and three replicates of 30 chicks per replicate. For six weeks, various doses of dry extract (17, 21, 25, 29 mg/kg) of E. purpurea were administered in drinking water to four treatment groups, and placebo was administered to the control group. All groups received Newcastle vaccines on days: 11, 19 and 38. Subsequently, on days 10, 25, 34 and 42, blood samples were taken from each group and Newcastle antibody titers were defined by HI test. This experiment showed that the use of E. purpurea in each of the foregoing doses had increasing effects on antibody titers, and this fact is significant between the control group and treatment groups. By using Duncan multiple range test, it was determined that this effect is significant in the case of 1st, 2nd and 3rd groups at 25th days results, but at 34th and 42nd days results, all groups show the same range of titers.

Key words: Echinacea purpurea, Newcastle vaccination, antibody titers, broiler chicks.