ENHANCEMENT OF GROWTH, IMMUNITY AND DISEASE RESISTANT TO
YERSINIA RUCKERI IN OREOCHROMIS NILOTICUS FINGERLINGS BY ORAL ADMINISTRATION OF PREBIOTIC (IMMUNOWALL®).
Rasha. M. Reda* and Khaled M. Selim
Department of Fish Diseases and Management, Faculty of Veterinary Medicine, Zagazig University, Zagazig, Egypt.
*Corresponding author: Rasha. M. Reda, Phone: +20-1006223528; Fax: +20-552283683
E-mail: [email protected]
|Received 11/ 6/ 2013||
Accepted 16/ 7/ 2013
A study was conducted to investigate the effect of Immunowall® commercial prebiotic on Oreochromis niloticus fingerlings. Three hundred and sixty fingerlings (8.7 ± 0.4g) were divided into 3 groups (group 1, 2 and 3) of 120 fish each to measure immunity and growth parameters. First group (G1) act as control fed on basal diet. The second (G2) and third (G3) groups were fed on diet supplemented with 1.5 and 3 g kg-1 Immunowall® respectively. After 30 days, G3 showed significant improvement in growth and feed utilization parameters followed by G2 compared with G1. At the end of the feeding period (60 days), such parameters did not significantly differ between G2 and G3 except in final body weight. In G3, the heights of the intestinal villi, numbers of goblet cells and numbers of intra-epithelial lymphocytes (IEL) had significant increases compared with control group. The protein and fat contents of the whole body in G3 was higher than G2 and G1. G3 had better effects than G2 on serum total protein and globulin levels. After 15 days of immunological study, G3 was significantly increased in percentage of serum killing and phagocytic activity than G2 and G1. G2 and G3 were higher than control group in lysozyme activity. While no difference between groups in nitric oxide. After 30 days, G3 showed significant increases in percentage of serum killing, phagocytic activity and nitric oxide compared with G1. The relative percentage survival of fish challenged by Yersinia ruckeri was showed enhancement by 60% in G3 and 15.38% in G2 than control.
Keywords: prebiotic, growth, immunity, Yersinia ruckeri, Oreochromis niloticus.