Using ATR-FT/IR molecular spectroscopy to detect effects of blend DDGS inclusion level on the molecular structure spectral and metabolic characteristics of the proteins in hulless barley

The objectives of this study were to investigate the effects of inclusion of a bioethanol co-product of blend DOGS (wheat:corn = 70%:30%) on protein molecular structure spectral and metabolic characteristics in hulless barley-based feed using ATR-FT/IR molecular spectroscopy. Hulless barley grain with the blend DDGS were mixed in the five ratios. The results showed that when blend DOGS was included at an increased ratio, predicted truly absorbed protein supply was highly and linearly increased (P < 0.05) from 98 to 245 g kg(-1) DM and degraded protein balance was increased (P < 0.05) from 1 to 75 g kg(-1) DM. The ratio of amide I toll peak area was increased (P < 0.05) in the original combination samples but decreased (P < 0.05) in the in situ 48 h residue samples. The ratio of alpha-helix to beta-sheet peak height was quadratically changed with increasing inclusion rate of blend DDGS in the original samples, but no difference among the in situ 48 h residue samples, indicating completion of protein degradation. No correlation was found between protein 2nd structures and protein nutrient profiles not only for the original combination samples (except NPN) but also for in situ 48 h residue samples. This study may provide information on how protein molecular structure and metabolic characteristic changes after feed combination and how more effectively utilize hulless barley and blend co-products for dairy and beef cattle. (C) 2012 Elsevier B.V. All rights reserved.