Molecular structure and metabolic characteristics of the proteins and energy in triticale grains and dried distillers grains with solubles for dairy cattle.

To our knowledge, there is no research on the molecular structure of triticale grain in comparison with other types of cereal grains and metabolic characteristics of the protein and energy in this grain and its coproducts, called dried distillers grains with solubles (DDGS), for dairy cattle. The objective of this study was to identify differences in molecular structures of proteins among grains and their DDGS using a molecular spectroscopy technique, namely, DRIFT, and to determine the nutrient profile and supply to dairy cattle. The protein molecular structure studies showed a difference (P < 0.01) in the amide I to amide II ratio and the α-helix to β-sheet ratio between grains and their DDGS. The energy content was similar for triticale grain and DDGS. There were differences in the protein and carbohydrate subfractions (P < 0.05) and the ruminal degradability of DM, CP, and NDF (P < 0.01) between triticale grain and DDGS. Triticale grain and DDGS had similar intestinal digestibility of rumen undegraded CP. However, triticale DDGS had higher (P < 0.01) predicted total metabolizable protein and degraded protein balance than triticale, indicating that triticale DDGS is a superior protein source for dairy cattle as compared with triticale grain. Bioethanol processing induced changes in the protein molecular structure.