NUTRITONAL IMPACT OF USING CITRONELLA (CYMBOPOGON NARDUS) BY-PRODUCT WITH OR WITHOUT ENZYMES MIXTURE SUPPLEMENTATION ON GROWTH PERFORMANCE OF GROWING RABBITS.

ABSTRACT: Growth performance, carcass traits, nutrient digestibility coefficients, some blood parameters and economical evaluation of APRI growing rabbits to diets containing graded levels of citronella by-product (CBP) as a replacement of clover hay was studied in the current study. A total number of 80 APRI growing rabbits, 6 weeks of age weighing 703 g±6.43. Rabbits were randomly distributed into 5 groups, each had 16 rabbits in 4 replicates 4 rabbits, each. The first group was fed the basal diet and served as a control group, the second and third groups were fed diet contained (20% CBP) and (40% CBP) citronella by-product in replacement of clover hay and represent 5.86% and 11.72% of the whole diets, respectively. The fourth and fifth groups were fed the same previous levels of CBP, but supplemented with enzymes mixture (Natuzyme fortified; E) at level of 0.35 g/kg diet and labeled (20% CBP+E) and (40% CBP+E), respectively. Enzymes mixture contains 6000 U cellulose, 11000 U  xylanase, 1500 U phytase, 700 U β-mannase, 700 U α-amylase and 700 U protease/ g. The results reveal that the group of 40% CBP+E achieved significantly the highest final weight with 5.8% improvement over the control and the best FCR than those of the control group, which was a associated with an increase in nutrients’ digestibility coefficients’ of CP, NFE and CF%, as well as enhancing carcass% and dressing %. In addition, 40% CBP+E group, recorded the cheapest price for producing 1 kg of rabbit meat and the best economic efficiency. It could be concluded that inclusion of citronella (Cymbopogonnardus) by-product up to 11.72% plus enzymes mixture of the whole diet is effective in improving rabbit’s growth performance in economic way.