EFFECT OF DIETARY CORN COBS AND ENZYMES SUPPLEMENTATION ON GROWING RABBITS PERFORMANCE

A total number of sixty weanling New Zealand White (NZW) rabbits aged five weeks old was used in this study. Rabbits were randomly distributed into 6 treatments, each one contains 5 males and 5 females. Three levels of corn cobs and two levels of enzymes preparation were used in a 3 x 2 factorial arrangement. Corn cobs were used at levels of 0 (control), 10 and 20 % of the diets. Enzymes preparation containing cellulase,  -glucanase,  -amylase, protease and lipase was added at 0 and 500 g/ ton of diet. Water and feed in pelleted form were offered ad-libitum during the experimental period from 5 to 12 weeks of age. The obtained results showed that rabbits fed the control and 10% corn cobs diets with enzymes recorded the significantly values of body weight, body weight gain and relative growth rate. The rabbits fed the control diet with enzymes consumed the highest amount of feed followed by those fed the control diet without enzymes then the 10% corn cobs with enzymes diet. The best feed conversion ratios were recorded for rabbits fed the diet containing 10% corn cobs with enzymes additions than those fed the control diet with enzymes addition compared with all other dietary treatments. Addition of enzymes in all experimental diets significantly improved digestibility coefficients of nutrients compared with those without enzymes addition. efficiency values. Conclusively , the present results showed that the use of corn cobs can be successfully fed at levels up to 10% of growing NZW rabbits diet supplemented with enzymes without adverse effect on growing rabbits performance. indicated that enzymes addition in rabbits diets significantly final BW, DBG and RGR compared with those of rabbits fed diets without enzymes addition. The improvement in live BW and DBG for rabbits fed the diet with enzyme addition may be due to the enhancing effect of enzymes on microflora growth in the gut and cecum as well as the increase in volatile fatty acids production and organic matter digestibility . These results agree with the finding of found that adding enzymes improved BW and DBG for rabbits fed dietary 10% crude that rabbits fed diets with kemzyme or showed an improvement in BW and DBG as compared with those fed the control diet. Moreover, found that 500 9 and 13 weeks of age. reported that rabbits fed diets with 500 and 750 mg kemzyme/kg feed significantly at 6 , 8 , 10 and 12 wks of age. showed that DBG of rabbits from 25 to 39 days of age was increased by 3.1 % as a result of including Porzyme and NSP digesting enzyme (Xylanase, Pectinase) from 25 to 39 days of age in diets. The data of this study revealed that enzymes addition in rabbits diets increased DFI significantly (P<0.05) increased consumed DFI compared with those without enzymes addition. These results are similar to those who found that average DFI of rabbits was increased due to adding optizyme which contains xylanase, protease, cellulase, hemocellulase and amylase at levels of 500 or 750 mg / kg feed. The data clear that enzymes addition in rabbit diets improved (P<0.05) FC compared with those without enzymes addition. The enhancement of FC as a result of adding enzymes may be due to the effect of enzymes in improving the digestibility of no significant changes in the levels of the albumin and globulin in the blood of rabbits supplemented with Protozin multi-enzymes (19 mg/kg diet) in the concentrate mixture. The present results of blood parameters are within the physiological normal values for rabbits reported by Abd El-Khalek et al. (2000) and Ashour (2001).