Chemical profile, rumen degradation kinetics, and energy value of four hull-less barley cultivars: comparison of the zero-amylose waxy, waxy, high-amylose, and normal starch cultivars

Interconnection between protein-related chemical functional group spectral features of prairie oat (Avena sativa L.) varieties and ruminant relevant nutrition-Degradation, intestinal digestion and true nutrient supply to dairy cows

To our knowledge, the study interconnection between inherent chemical functional group spectral features and nutrient utilisation is still limited. The objective of this study was to test the adequacy of vibrational Fourier transform infrared attenuated total reflectance (ATR-FTIR) spectroscopy as a fast tool to assess the interactive relationship between the nutritive value of the Prairie cool-season oat (Avena sativa L.) varieties in dairy cows and inherent chemical functional group spectral features. The chemical functional group spectral features of the Prairie cool-season oat varieties in western Canada were determined by Fourier transform infrared attenuated total reflectance spectroscopy. The protein-related spectral parameters of chemical functional groups included peak height and peak area intensity of Amide I, Amid II, protein structural α-helix and β-sheet, and their ratios. The rumen degradation kinetics were determined using in situ techniques with four rumen-canulated lactating dairy cows. The intestinal digestion was evaluated using a three-step in vitro technique with 12 h preincubation. The experiment was an randomized complete block design. The data were analysed using the mixed-model procedure of the Statistical Analysis System. The results showed that the interconnection between rumen degradation kinetics, intestinal digestion and true nutrient supply to dairy cows and protein-related chemical functional group spectral features could be revealed by ATR-FTIR with univariate and multi-variate spectral analyses. These findings indicate that ruminant relevant nutritive value of cool-season oats could be rapidly evaluated and predicted using oat-specific functional group spectral characteristics which could be obtained by a non-distractive bioanalytical tool of ATR-FTIR 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 to reveal association of steam-flaking induced carbohydrates molecular structural changes with grain fractionation, biodigestion and biodegradation

Advanced vibrational molecular spectroscopy has been developed as a rapid and non-destructive tool to reveal intrinsic molecular structure conformation of biological tissues. However, this technique has not been used to systematically study flaking induced structure changes at a molecular level. The objective of this study was to use vibrational molecular spectroscopy to reveal association between steam flaking induced CHO molecular structural changes in relation to grain CHO fractionation, predicted CHO biodegradation and biodigestion in ruminant system. The Attenuate Total Reflectance Fourier-transform Vibrational Molecular Spectroscopy (ATR-Ft/VMS) at SRP Key Lab of Molecular Structure and Molecular Nutrition, Ministry of Agriculture Strategic Research Chair Program (SRP, University of Saskatchewan) was applied in this study. The fractionation, predicted biodegradation and biodigestion were evaluated using the Cornell Net Carbohydrate Protein System. The results show that: (1) The steam flaking induced significant changes in CHO subfractions, CHO biodegradation and biodigestion in ruminant system. There were significant differences between non-processed (raw) and steam flaked grain corn (P<.01); (2) The ATR-Ft/VMS molecular technique was able to detect the processing induced CHO molecular structure changes; (3) Induced CHO molecular structure spectral features are significantly correlated (P<.05) to CHO subfractions, CHO biodegradation and biodigestion and could be applied to potentially predict CHO biodegradation (R²=0.87, RSD=0.74, P<.01) and intestinal digestible undegraded CHO (R²=0.87, RSD=0.24, P<.01). In summary, the processing induced molecular CHO structure changes in grain corn could be revealed by the ATR-Ft/VMS vibrational molecular spectroscopy. These molecular structure changes in grain were potentially associated with CHO biodegradation and biodigestion.

Relationship of carbohydrates and lignin molecular structure spectral profiles to nutrient profile in newly developed oats cultivars and barley grain

The objectives of this study were to quantify the chemical profile and the magnitude of differences in the oat and barley grain varieties developed by Crop Development Centre (CDC) in terms of Cornell Net Carbohydrate Protein System (CNCPS) carbohydrate sub-fractions: CA4 (sugars), CB1 (starch), CB2 (soluble fibre), CB3 (available neutral detergent fibre - NDF), and CC (unavailable carbohydrate); to estimate the energy values; to detect the lignin and carbohydrate (CHO) molecular structure profiles in CDC Nasser and CDC Seabiscuit oat and CDC Meredith barley grains by using Fourier transform infrared attenuated total reflectance (FTIR-ATR); to develop a model to predict nutrient supply based on CHO molecular profile. Results showed that NDF, ADF and CHO were greater (P<0.05) in oat than in barley. The starch content was greater (P<0.05) in barley than in oat. The CDC Meredith showed greater total rumen degradable carbohydrate (RDC), intestinal digestible fraction carbohydrate (FC) and lower total rumen undegradable carbohydrate (RUC). However, the estimated milk production did not differ for CDC Nasser oat and CDC Meredith barley. Lignin peak area and peak height did not differ (P>0.05) for oat and barley grains as well as non-structural CHO. However, cellulosic compounds peak area and height were greater (P<0.05) in oat than barley grains. Multiple regressions were determined to predict nutrient supply by using lignin and CHO molecular profiles. It was concluded that although there were some differences between oat and barley grains, CDC Nasser and CDC Meredith presented similarities related to chemical and molecular profiles, indicating that CDC Meredith barley could be replaced for CDC Nasser as ruminant feed. The FTIR was able to identify functional groups related to CHO molecular spectral in oat and barley grains and FTIR-ATR results could be used to predict nutrient supply in ruminant livestock systems.

Molecular basis of processing-induced changes in protein structure in relation to intestinal digestion in yellow and green type pea (Pisum sativum L.): A molecular spectroscopic analysis

The objectives of this study were (1) to quantify the protein inherent molecular structural features of green cotyledon (CDC Striker) and yellow cotyledon (CDC Meadow) pea (Pisum sativum L.) seeds using molecular spectroscopic technique (FT/IR-ATR); (2) measure the denaturation of protein molecular makeup in the two types of pea during dry roasting (120°C for 60 min), autoclaving (120°C for 60 min) or microwaving (for 5 min); and (3) correlate the heat-induced changes in protein molecular makeup to the corresponding changes in protein digestibility determined using modified three-step in vitro procedure. Compared with yellow-type, the green-type peas had higher (P<0.05) ratios of amide I to II peak height (1.698 vs. 1.805) and area (1.843 vs. 2.017). A significant correlation was observed between the amide I and II peak height (r=0.48) and peak area (r=-0.42) ratio with protein content. Compared with yellow-type, the green-type peas had lower (P<0.05) α-helix:β-sheet ratio (1.015 vs. 0.926), indicating varietal difference in protein secondary structure makeup. All processing applications increased α-helix:β-sheet ratio, with the largest (P<0.05) increase being observed with roasting and microwaving. The heat-induced changes in α-helix:β-sheet ratio was strongly correlated to intestinal digestibility of protein within the green (r=-0. 86) and yellow (r=0.81) pea-types. However, across the pea types the correlation was not significant. Principal component and hierarchical cluster analyses on the entire spectral data from the amide region (ca. 1727-1480 cm(-1)) were able to visualize and discriminate the structural difference between pea varieties and processing treatments. This study shows that the molecular spectroscopy can be used as a rapid tool to screen the protein value of raw and heat-treated peas.

Effect of waxy (Low Amylose) on Fungal Infection of Sorghum Grain

Loss of function mutations in waxy, encoding granule bound starch synthase (GBSS) that synthesizes amylose, results in starch granules containing mostly amylopectin. Low amylose grain with altered starch properties has increased usability for feed, food, and grain-based ethanol. In sorghum, two classes of waxy (wx) alleles had been characterized for absence or presence of GBSS: wx(a) (GBSS(-)) and wx(b) (GBSS(+), with reduced activity). Field-grown grain of wild-type; waxy, GBSS(-); and waxy, GBSS(+) plant introduction accessions were screened for fungal infection. Overall, results showed that waxy grains were not more susceptible than wild-type. GBSS(-) and wild-type grain had similar infection levels. However, height was a factor with waxy, GBSS(+) lines: short accessions (wx(b) allele) were more susceptible than tall accessions (undescribed allele). In greenhouse experiments, grain from accessions and near-isogenic wx(a), wx(b), and wild-type lines were inoculated with Alternaria sp., Fusarium thapsinum, and Curvularia sorghina to analyze germination and seedling fitness. As a group, waxy lines were not more susceptible to these pathogens than wild-type, supporting field evaluations. After C. sorghina and F. thapsinum inoculations most waxy and wild-type lines had reduced emergence, survival, and seedling weights. These results are valuable for developing waxy hybrids with resistance to grain-infecting fungi.

New starch phenotypes produced by TILLING in barley

Barley grain starch is formed by amylose and amylopectin in a 1∶3 ratio, and is packed into granules of different dimensions. The distribution of granule dimension is bimodal, with a majority of small spherical B-granules and a smaller amount of large discoidal A-granules containing the majority of the starch. Starch granules are semi-crystalline structures with characteristic X-ray diffraction patterns. Distinct features of starch granules are controlled by different enzymes and are relevant for nutritional value or industrial applications. Here, the Targeting-Induced Local Lesions IN Genomes (TILLING) approach was applied on the barley TILLMore TILLING population to identify 29 new alleles in five genes related to starch metabolism known to be expressed in the endosperm during grain filling: BMY1 (Beta-amylase 1), GBSSI (Granule Bound Starch Synthase I), LDA1 (Limit Dextrinase 1), SSI (Starch Synthase I), SSIIa (Starch Synthase IIa). Reserve starch of nine M3 mutant lines carrying missense or nonsense mutations was analysed for granule size, crystallinity and amylose/amylopectin content. Seven mutant lines presented starches with different features in respect to the wild-type: (i) a mutant line with a missense mutation in GBSSI showed a 4-fold reduced amylose/amylopectin ratio; (ii) a missense mutations in SSI resulted in 2-fold increase in A:B granule ratio; (iii) a nonsense mutation in SSIIa was associated with shrunken seeds with a 2-fold increased amylose/amylopectin ratio and different type of crystal packing in the granule; (iv) the remaining four missense mutations suggested a role of LDA1 in granule initiation, and of SSIIa in determining the size of A-granules. We demonstrate the feasibility of the TILLING approach to identify new alleles in genes related to starch metabolism in barley. Based on their novel physicochemical properties, some of the identified new mutations may have nutritional and/or industrial applications.

Optimized utilization of the co-products from bioethanol processing and oat grain: effect of blending on biochemical, biodegradation, and nutritional profiles

The objective of this study was to (1) optimize the utilization of wheat-based dried distillers grains with soluble (wDDGS) by blending with oat ( Avena sativa L.) grain as an alternative feed for beef cattle when the barley price is high and (2) investigate the effect of blending on biochemical, biodegradation, and nutritional profiles. Oat grains were blended with wDDGS produced in western Canada at different levels (4:0, 3:1, 2:2, and 1:3 on %DM basis in two batches, denoted O0, O25, O50, and O75, respectively). The study revealed that increasing the wDDGS resulted in increasing most nutrient contents linearly (P < 0.05) except for starch and cell wall materials, which were linearly decreased (from 43.6 to 12.0% and from 34.5 to 29.1% of DM for starch and NDF, respectively). When wDDGS was increased in the blend/mixture, intestinally absorbable protein and degradable balance of protein increased (P < 0.05). Overall, through blending or combining with the cereal grain, the co-products from bioethanol processing could be optimally utilized. The best combination of oat to wDDGS ratio was 75% to 25%.

Investigating the molecular structural features of hulless barley (Hordeum vulgare L.) in relation to metabolic characteristics using synchrotron-based fourier transform infrared microspectroscopy

The synchrotron-based Fourier transform infrared microspectroscopy (SR-FTIRM) technique was used to quantify molecular structural features of the four hulless barley lines with altered carbohydrate traits [amylose, 1-40% of dry matter (DM); β-glucan, 5-10% of DM] in relation to rumen degradation kinetics, intestinal nutrient digestion, and predicted protein supply. Spectral features of β-glucan (both area and heights) in hulless barley lines showed a negative correlation with protein availability in the small intestine, including truly digested protein in the small intestine (DVE) (r = -0.76, P < 0.01; r = -0.84, P < 0.01) and total metabolizable protein (MP) (r = -0.71, P < 0.05; r = -0.84, P < 0.01). Variation in absorption intensities of total carbohydrate (CHO) was observed with negative effects on protein degradation, digestion, and potential protein supply (P < 0.05). Molecular structural features of CHO in hulless barley have negative effects on the supply of true protein to ruminants. The results clearly indicated the impact of the carbohydrate-protein structure and matrix.

Evaluation of the feed value for ruminants of blends of corn and wheat distillers dried grains

Recently, biofuel processing has produced a large amount of biofuel coproducts. However, to date, there is little information on the metabolic characteristics of proteins and energy in biofuel coproduct-based rations. The objective of this study was to study the metabolic characteristics of proteins and energy in biofuel coproduct-based rations in terms of (1) chemical and nutrient profiles, (2) protein and carbohydrate subfraction associated with various degradation rate, (3) rumen and intestinal degradation and digestion kinetics, and (4) metabolic characteristics of proteins. Two sources of grain corn were mixed with two sources of biofuel coproducts (wheat-based dried distillers grains with solubles, wDDGS) in ratios of 100:0, 75:25, 50:50, and 25:75%. The study revealed that increasing the biofuel coproduct inclusion level increased most of the nutritional components linearly (P < 0.05) except starch, which linearly decreased. With increasing biofuel coproduct inclusion level, the rumen degradation rate and the effective degradability of organic matter were not affected (P > 0.05), but the effective degradability of starch was decreased (P < 0.05). Effective degradation of crude protein and neutral detergent fiber as well as predicted truly absorbed protein supply in the small intestine and degraded protein balance were increased (P < 0.05). In conclusion, the inclusion of the biofuel coproduct up to 25-50% in rations improved potential nitrogen and energy synchronization for microbial growth and improved truly absorbable protein supply to the small intestine, without altering energy value.

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 DDGS (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 DDGS 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 to II 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 α-helix to β-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.

Relationship of carbohydrate molecular spectroscopic features in combined feeds to carbohydrate utilization and availability in ruminants

To date, there is no study on the relationship between carbohydrate (CHO) molecular structures and nutrient availability of combined feeds in ruminants. The objective of this study was to use molecular spectroscopy to reveal the relationship between CHO molecular spectral profiles (in terms of functional groups (biomolecular, biopolymer) spectral peak area and height intensity) and CHO chemical profiles, CHO subfractions, energy values, and CHO rumen degradation kinetics of combined feeds of hulless barley with pure wheat dried distillers grains with solubles (DDGS) at five different combination ratios (hulless barley to pure wheat DDGS: 100:0, 75:25, 50:50, 25:75, 0:100). The molecular spectroscopic parameters assessed included: lignin biopolymer molecular spectra profile (peak area and height, region and baseline: ca. 1539-1504 cm(-1)); structural carbohydrate (STCHO, peaks area region and baseline: ca. 1485-1186 cm(-1)) mainly associated with hemi- and cellulosic compounds; cellulosic materials peak area (centered at ca. 1240 cm(-1) with region and baseline: ca. 1272-1186 cm(-1)); total carbohydrate (CHO, peaks area region and baseline: ca. 1186-946 cm(-1)). The results showed that the functional groups (biomolecular, biopolymer) in the combined feeds are sensitive to the changes of carbohydrate chemical and nutrient profiles. The changes of the CHO molecular spectroscopic features in the combined feeds were highly correlated with CHO chemical profiles, CHO subfractions, in situ CHO rumen degradation kinetics and fermentable organic matter supply. Further study is needed to investigate possibility of using CHO molecular spectral features as a predictor to estimate nutrient availability in combined feeds for animals and quantify their relationship.

Effect of wheat-based dried distillers' grains with solubles inclusion on barley-based feed chemical profile, energy values, rumen degradation kinetics, and protein supply

The objectives of this study were to determine the effect of replacing the barley grain portion of the diet by wheat-based dried distillers' grains with solubles (wDDGS) at graded levels on feeding value for beef cattle. Two cultivars of barley were mixed with two sources of wDDGS in ratios of 100:0, 75:25, 50:50, and 25:75% (weight DM basis; denoted B0, B25, B50, and B75, respectively). This study revealed that increasing wDDGS inclusion level increased most of the nutritional composition linearly except for starch, which linearly decreased (from 609 to 320 g/kg of DM). Soluble, slowly degradable, and undegradable Cornel Net Carbohydrate and Protein System (CNCPS) protein and carbohydrate fractions linearly increased with increasing wDDGS inclusion level, whereas their rapidly and intermediately degradable fractions decreased. With increasing wDDGS inclusion, the rumen degradation rate of all measured parameters decreased linearly, the extent of degradability of organic matter was not affected, and the extent of CP degradability (g/kg DM) as well as the predicted protein supply in the small intestine and degraded protein balance in the rumen was increased. The inclusion of wDDGS in barley-based diets up to 50% did not alter energy values of the diet. Furthermore, optimum N to energy balance of the feed mixture for microbial growth in the rumen was reached by replacing 25% of barley by wDDGS. Thus, the nutritive value of the barley-based diets is manipulated by including wDDGS, which can be used to overcome the shortcomings of barley-dominated diets for beef cattle.