The Effect of Heat or Heat-Xylose Processing on Nitrogen Fractions and in Situ/In Vitro Ruminal and Post-Ruminal Protein Disappearance of Guar Meal
Hossein Jahani-Azizabadi, Mohsen Danesh Mesgaran, Ali Reza Vakili, Moosa Vatandoost, Einollah Abdi Ghezeljeh and Mohsen Mojtahedi
DOI : 10.3844/ajavsp.2010.266.273
American Journal of Animal and Veterinary Sciences
Volume 5, Issue 4
Problem statement: Guar meal is a by-product consisting of hull and germ and is mostly used as a protein source in poultry and ruminant rations. The aim was to determine the effect of heat or heat-xylose processing on nitrogen fractions, in situ ruminal degradation parameters and in situ/in vitro ruminal and post-ruminal disappearance of guar meal. Approach: Samples were intact Guar Meal (GM), heat processed GM (GMhp, GM was heated at 100°C for 45 minute using industrial heater) and heat-xylose processed GM (GMhx, xylose was included in GM to give a final concentration of 10 g kg−1 DM, then was heat processed at 100°C for 45 minute using industrial heater). Ruminal degradation parameters of DM and Crude Protein (CP) were determined by in situ technique using four ruminally fistulated sheep. Post-ruminal disappearance of ruminal-undegradable CP was determined on residue from 16 h ruminal incubation of guar meal samples by three-step in situ/in vitro enzymatic procedure. Results: Non-protein nitrogen of the GMhx and GM samples ranged from 218-319 (g kg−1 N). Acid detergents insoluble nitrogen concentration of both GM and GMhp was significantly lower than that of GMhx (10.3, 11.29 and 18.53 g kg−1 nitrogen, respectively). In situ fractional degradation rate constant (c) of DM and CP was significantly decreased as a result of heat-xylose processing. Effective crude protein degradability of GMhp and GMhx was higher than that of GM. Post-ruminal disappearance of ruminal-undegradable CP of GM hx (0.965) was significantly higher compared with GM and GMhp (0.918 and 0.906, respectively). Conclusion: Results of the present study demonstrated that heat and heat-xylose processing might effectively protect the DM and CP of guar meal from ruminal degradation.
© 2010 Hossein Jahani-Azizabadi, Mohsen Danesh Mesgaran, Ali Reza Vakili, Moosa Vatandoost, Einollah Abdi Ghezeljeh and Mohsen Mojtahedi. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.