Protein molecular structure in relation to predicted biodegradation and nutrient supply of feedstocks and co-products from bio-oil processing with CNCPS system: Comparison Crusher Plants within Canada and within China as well as between Canada and China

Abstract

Recently, rapid non-invasive advanced vibrational molecular spectroscopy has been developed to detect tissue inherent molecular structure. However, this advanced technique is seldom known by animal scientists and seldom used to study feed molecular structure in relation to nutrient utilization and availability in animals. The objectives of this study were to 1) detect the interactive association between the processing-induced protein molecular structure changes and biodegradation and intestinal digestion in ruminants using advanced vibrational molecular spectroscopy, and 2) develop a model to predict protein and carbohydrate degradation and digestions based on feed inherent protein molecular structure. The feed used for this study were various sources of feedstock (oil seeds) and co-products (canola meal, canola pellets) from ten different crushing plants in Canada and China with multi-source samples from each crushing plant. The predictable protein and carbohydrate degradable sub-fractions and nutrient supply of sub-fractions to dairy cows were evaluated with the updated Cornell Net Carbohydrate and Protein System (CNCPS 6.5). The protein molecular structure was revealed using advanced vibrational molecular spectroscopy (FT/IR-ATR). The molecular structure spectral analyses were carried out using uni- and multi-variate molecular spectral analyses. The model variable selection was carried out using SAS with a Stepwise option. The results showed that protein molecular structure spectral characteristics could be used to predict CNCPS protein and carbohydrate nutrient supply to dairy cows. Strong positive correlation was found in canola meal between rumen degraded PA2 and amide I area (r = 0.67, P < 0.001), amide I height (r = 0.73, P < 0.001), and α-helix height (r = 0.83, P < 0.001). RDPB2 was negatively correlated with α-helix height (r = −0.69, P < 0.001). Moreover, TRDC was negatively correlated with amide I area (r=-0.64, P < 0.001), amide I height (r = −0.65, P < 0.001), and α-helix height (r = −0.62, P < 0.001). It was concluded that protein and carbohydrate degradable and undegradable sub-fractions had interactive associations with the processing-induced protein molecular structure changes in co-products from bio-oil processing.