REPLACEMENT OF DIETARY YELLOW CORN BY WHEAT BRAN WITH OR WITHOUT MULTI-ENZYMES OR PREBIOTIC SUPPLEMENTATION ON NUTRIENT DIGESTIBILITY AND BLOOD PARAMETERS IN GROWING RABBITS

Abstract

The present study was performed to investigate the influence of feeding diets contained three levels of yellow corn (YC) without or with enzymes and/or prebiotics on the nutrient digestibility and blood parameters of growing New Zealand White (NZW ) rabbits. A feeding trial (3x4) with factorial arrangement of treatment was carried out. The chemical analyses for experimental diets and faces and blood constituents were run. One hundred and eight, 6 weeks old weaning NZW rabbits were used in this study. Rabbits were randomly distributed into 12 equal experimental groups; each contained three equal replicates. The digestibility coefficients of dry matter (DM), organic matter (OM), crude fiber (CF), ether extract (EE), nitrogen free extract (NFE), non-ditrgant fiber (NDF), ADF and hemicellulose were increased with feeding on 15 % YC diets than those of rabbits fed on 5 % or 10 % YC rations, but there was no significant effect of dietary treatments on DMI and CP digestibility. Rabbits fed enzyme-supplemented diets displayed significantly lower DM, OM, CF, EE, NFE, NDF, ADF and hemicellulose than those of other dietary treatments. There was no significant effect of these supplements on DMI (g/d) and CP digestibility, compared with the control diet (without supplements). The digestible DCP (%), TDN% and DEI (kcal/d) were significantly higher (P≤0.05) for animals fed diets containing 15 % YC than feeding on 5 or 10 % YC diets, while there were no significant effect on TDNI (g/d), CPI (g/d) and DEI (kcal/d). Rabbits fed the enzyme-supplemented diets exhibited significantly lower TDN (%) and DE (kcal/kg) than did those fed other experimental diets. Similarly, significantly lower means of DEI (kcal/d) were recorded by rabbits fed enzyme- or enzyme plus prebiotics-supplemented diets compared with other experimental groups of rabbits, but DCP % and CPI (g/d) were not affected. The plasma levels of triglycerides and total cholesterol were significantly lower for rabbits fed diets with 10 % or 15 % YC than those of rabbits fed the lowest level of YC,, while there was no significant effect on ALT, AST, total protein or urea concentration. Rabbits fed the diets fortified with enzymes plus prebiotics exhibited significantly lower (P≤0.05) levels of plasma urea and triglycerides and significantly higher cholesterol concentration than did the control group. In conclusion, using YC to partially replace wheat bran in growing rabbits diets had no negative effect on the nutritive value of diets. The nutritive value of the experimental diets for growing rabbits could increase by supplementing enzymes plus prebiotics. The present study showed that feeding growing rabbits on diets contained 10 % YC without supplements or feeding on diets contained 15 % YC with enzymes and prebiotics are effective for nutrient digestibility, nutritive value and health status of rabbits.