Effect of purple coneflower (Echinacea purpurea) extract on the performance, cellular and humoral immune responses of broiler chicks

The experiment was conducted by using of 240 day old broilers cob with an average live weight of 44. 6 g to determine the effect of of purple coneflower extract on the performance and immune reponses. The extract of purple coneflower containing 2. 99 mg/ml caffeic acid was added in the levels of zero control group (Ezero)، 0. 5 (E0. 5)، 1 (E1)، 1. 5 (E1. 5)، 2 (E2) and 2. 5 (E2. 5) ml/l to drinking water from day 6 to 42. Cellular immune responses were assayed by PHA-P injection in the skin fold of wings and thickness of skin were measured after 24 and 48h. A 25% SRBC suspension were injected in the breast muscle to investigate humoral immune responses، and titers IgG and IgM anti SRBC was determined by haemagglutination test. Results indicated that the using 1≥ 1ml of purple coneflower extract improved daily live weight gain and feed conversion ratio (p<0. 05). Treatment E1 gained the highest daily live weight (67. 98) and the lowest feed conversion ratio (1. 54). The using of purple coneflower extract improved cellular immune responses and IgG titer against SRBC (p<0. 05). The highest of IgG titer against SRBC and cellular immune response were achieved by using 2. 5 ml extract (p<0. 05). Treatment E2. 5 had the highest burs and thymus percentage weight (p<0. 05). Overall results showed that continuous use of 1 ml of extract/l of drinking water of broiler chicks caused to improve performance and immune responses.