الفهرس 
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Abstract
The present work was carried out at the Rabbit Research Farm and laboratories of the Animal Production Department, Faculty of Agriculture, Zagazig University, Zagazig, Egypt. This study was conducted to explored the effects of graded levels of dietary two forms of chitosan(first experiment) and curcumin (second experiment)on the growth performance indicators, total tract apparent digestibility, slaughter traits, immune function, cecal microbiota, and intestinal morphology in growing male rabbits.In the first experiment, a total of 120 growing New Zealand White (NZW) rabbits (male, 35 days of age, 573.22 ± 6.95g) were divided into 8 similar groups in a 2 × 4 factorial design; i.e., 2 chitosan forms (traditional and nano) ×4 dietary levels(0, 250, 500, 1000 mg/ kg diet).In the second experiment, 60 male rabbits aged 35 days (570.29 ± 12.26 g) were arbitrarily allocated to four groups. The experimental groups included: the control group (without curcumin supplementation), supplementation of 100, 300 or 500 mg curcumin per kg diet. The feeding on the experimental diet was continued for 56 days.The results of the first experiment showed that All tested feed additives significant improvement of live body weight , daily body weight gain and feed conversion ratio. Nutrient digestibility and nutritive values were not significantly affected by dietary chitosan form. The serum IgM level increased significantlyin rabbits fed diet supplemented with nano-chitosan. No significant differences were observed between both chitosan forms in all measured hematological parameters. Pre-slaughter weight, actual carcass weight and dressing percentage affected insignificantly with chitosan form. Also, adjusted weights of carcass, internal organs and carcass cuts insignificantly affected with chitosan form, except fore-part, hind-part and prim cuts significantly (P<0.001) affected. Coliforms and Salmonella spp counts decreased significantly (P<0.001) in rabbits fed diets supplemented with nano-chitosan compared with those in the traditional chitosan groups. Cryptdepth and goblet cells increased (P<0.001) while muscle layer decreased in rabbit fed diets supplemented with nano-chitosan compared with the traditional form of chitosan. The results of the second experiment revealed that curcumin supplemented with 500 mg recorded higher Final live body weight, the daily body gain weight, relative growth rate, feed intake , the best feed conversion and digestibility of dry matter, ether extract, crude protein and organic matter values as well as total digestible nutrients, digestible crude protein and digestible energy values. curcumin supplementation recorded higher hemoglobin, red blood cells, hematocrit, MCV, MCH,and lymphocyte concentration curcumin showed a significant increase in immune indicators (complement C3, Immunoglobulin M, and lysozyme activity). Supplementation of curcumin was insignificantly affected all carcass traits, except hind-part and intermediate-part significantly . Rabbits fed diet supplemented with 500 mg curcumin recorded a greater count of lactobacilli when compared with other groups. Villus length and width, crypt depth, and goblet cells increased significantly with curcumin supplementation in rabbit diets. In conclusion rabbits who received 1000 mg nano-chitosan/kg diet had the best growth performance, feed conversion, intestinal histomorphometry, immune response, return from body gain, and final margin and low counts of cecal pathogenic bacteria. On the other hand, dietary curcumin extract at 500 mg/kg improved growth performance, nutrient digestibility, nutritive values, blood constituents, immunity, intestinal morphology, cecal microbiota and the final margin of growing rabbits.The study suggests supporting the commercial production of chitosan as nanoparticles for animal nutrition. Thus, from both a health and economic point of view, several benefits might be gained by adding these additives (chitosan, nano-chitosan, and curcumin extract) to the diet of commercial rabbits.