Curve-linear relationship between altered carbohydrate traits with molecular structure and truly absorbed nutrient supply to dairy cattle in new hulless barley ( Hordeum vulgare L.)

Using advanced vibrational molecular spectroscopy (ATR-Ft/IRS and synchrotron SR-IMS) to study an interaction between protein molecular structure from biodegradation residues and nutritional properties of cool-climate adapted faba bean seeds

The objective of this study was to use advanced vibrational molecular spectroscopy (ATR-Ft/IRS) to study an interaction between legume protein molecular structure from biodegradation residues and nutritional properties of newly developed genotypes of cool-climate adapted faba bean seed with low and normal tannin levels grown in western Canada. Protein molecular structures including amide I, II areas and peak heights, α-helix and β-sheet peak heights in rumen biodegradation residues were determined by using attenuated total reflectance Fourier transform infrared molecular spectroscopy (ATR-FTIR). The nutritional properties were determined which included chemical and nutrient profiles, in situ rumen degradation kinetics, rumen protein degradation, and intestinal protein digestion in the newly developed genotypes of faba bean seeds with low and normal tannin levels. The results showed that the spectral intensity of faba bean varieties with a normal tannin level in rumen biodegradation residues was greater (P < 0.05) than that with a low tannin level. The spectral intensity of amide I, II areas and peak heights, α-helix and β-sheet peak heights in all genotypes (except the variety of Snowdrop) in biodegradation residuals of faba bean seeds had a unique pattern with increasing first and then decreasing with the increasing of rumen incubation time. The molecular structures of protein (α-helix, ratio of α-helix to β-sheet height and amide I to II area, R² > 0.6) were associated with in situ degradation kinetics - soluble (S) and potential degradable fractions (D) and rumen protein degradation- bypass or undegraded protein (BCP or RUP). The molecular spectral parameters in the FTIR fingerprint region didn't form cluster among different genotypes in residual faba bean seeds in 12 h and 24 h incubation, which indicate they had similar protein molecular structures after incubation. In conclusion, there was an interaction between protein molecular structure from biodegradation residues and nutritional properties of newly developed cool-climate adapted faba bean seeds with normal and low level of tannin. The cool-climate adapted genotype had an impact on the protein molecular structure, and the protein utilization and metabolism were predictable from protein spectral molecular structures after rumen biodegradation with ATR-Ft/IRS spectroscopy.

Interactive Curve-Linear Relationship Between Alteration of Carbohydrate Macromolecular Structure Traits in Hulless Barley (Hordeum vulgare L.) Grain and Nutrient Utilization, Biodegradation and Bioavailability

The aim of this study was to reveal an interactive curve-linear relationship between altered carbohydrate macromolecular structure traits of hulless barley cultivars and nutrient utilization, biodegradation, as well as bioavailability. The cultivars had different carbohydrate macromolecular traits, including amylose (A), amylopectin (AP), and β-glucan contents, as well as their ratios (A:AP). The parameters assessed included: (1) chemical and nutrient profiles; (2) protein and carbohydrate sub-fractions partitioned by the Cornell Net Carbohydrate and Protein System (CNCPS); (3) total digestible nutrients (TDN) and energy values; and (4) in situ rumen degradation kinetics of nutrients and truly absorbed nutrient supply. The hulless barley samples were analyzed for starch (ST), crude protein (CP), total soluble crude protein (SCP), etc. The in situ incubation technique was performed to evaluate the degradation kinetics of the nutrients, as well as the effective degradability (ED) and bypass nutrient (B). Results showed that the carbohydrates (g/kg DM) had a cubic relationship (p < 0.05), with the A:AP ratio and β-glucan level; while the starch level presented a quadratic relationship (p < 0.05), with the A:AP ratio and cubic relationship (p < 0.05), with β-glucan level. The CP and SCP contents had a cubic relationship (p < 0.05) with the A:AP ratio and β-glucan level. The altered carbohydrate macromolecular traits were observed to have strongly curve-linear correlations with protein and carbohydrate fractions partitioned by CNCPS. For the in situ protein degradation kinetics, there was a quadratic effect of A:AP ratio on the rumen undegraded protein (RUP, g/kg DM) and a linear effect of β-glucan on the bypass protein (BCP, g/kg DM). The A:AP ratio and β-glucan levels had quadratic effects (p < 0.05) on BCP and EDCP. For ST degradation kinetics, the ST degradation rate (K_d), BST and EDST showed cubic effects (p < 0.05) with A:AP ratio. The β-glucan level showed a cubic effect on EDST (g/kg DM) and a quadratic effect on BST (g/kg ST or g/kg DM) and EDST (g/kg DM). In conclusion, alteration of carbohydrate macromolecular traits in hulless barley significantly impacted nutrient utilization, metabolic characteristics, biodegradation, and bioavailability. Altered carbohydrate macromolecular traits curve-linearly affected the nutrient profiles, protein and carbohydrate fractions, total digestible nutrient, energy values, and in situ degradation kinetics.

Using vibrational molecular spectroscopy with chemometrics as an analytical method to investigate association of degradation with inherent molecular structures in grain

Corn starch played a critical role in maintaining energy supply for high milk yield. The objectives of this research were to disclose the starch and carbohydrate-related biopolymers degradation in three newly developed corn lines (LM10, LM01 and LD999) during rumen incubation, and detect relationships between molecular structures and starch degradation. Attenuated Total Reflectance Fourier-transform Vibrational Molecular Spectroscopy (ATR-Ft/VMS) was applied to reveal molecular structure conformations that were associated with major nutrients macro-biopolymers. Line LM01 was greater (P < 0.01) in peak heights and areas of carbohydrate (CHO) related spectral than LM10 and LD999 (P < 0.01). Line LM01 had greater rumen degradable dry matter and starch than LM10 and LD999 (P < 0.05). During 48 h rumen incubation, absorbance intensities of CHO peak 1 and peak 3 decreased linearly (P < 0.01), but absorbance intensities of CHO peak 2 increased, non-structural CHO related spectral absorbance intensities decreased linearly (P < 0.01). Correlation analysis showed that CHO associated spectral were positively correlated to ruminal dry matter and starch degradability (P < 0.10). The results inferred that the molecular spectral features of newly developed corn lines played a more important role in determining starch degradability.