This study was conducted to assess the effect of Citrus limon powder (CLP) as immune-enhancer phytobiotic of growing New Zealand White rabbits (NZW). Forty eight growing rabbits were randomly allocated to three equal groups in a Randomized Complete Design (RCD). Rabbit groups were fed a basal diet served as control group, while the other two groups were fed basal diet mixed with CLP dosed at 10 and 20g/kg of feed, respectively. After 7 weeks of the experiment rabbits were injected with sheep red blood cells (SRBC's) as immunizing agent then blood samples were taken 7 days later. Serum titers (log2) for both total antibody and mercaptoethanol (ME)-sensitive antibody to detect IgG were assayed by microtiter procedures. Sections of the immune-organs were collected from same rabbits for histological investigations. The results of the cell mediated immune-responses showed highly significant difference (p<0.01) in the values of total and differential leukocytes, and chemokinetic movement and phagocytic activity as well as, humoral immune-responses (TIg, IgG, IgM and precipitation test) significantly (p<0.01) affected by feeding growing rabbits on 10 and 20g CLP compared with those fed control diet. Moreover, histological structure of thymus and spleen of treated rabbits showed normal structure.
In conclusion, 10 and 20g CLP/kg diet enhance growing rabbit immune-responses with normal immune organ structure.