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

Digestibility of amino acids in pigs fed distillers dried grains with solubles derived from corn, sorghum, and triticale

An experiment was conducted to determine the standardized ileal digestibility (SID) of amino acids (AA) in distillers dried grains with solubles derived from corn (C-DDGS), sorghum (S-DDGS), and triticale (T-DDGS) fed to growing pigs. A total of 16 barrows [initial body weight (BW) = 23.1 ± 2.03 kg] surgically fitted with T-cannulas at the distal ileum were divided into four groups based on BW and assigned to a quadruplicated 4 × 2 incomplete Latin square design with four dietary treatments and two experimental periods. Three diets containing C-DDGS, S-DDGS, or T-DDGS, as well as a nitrogen-free diet, were fed in each experimental period consisting of 5 d of adaptation and 2 d of ileal digesta collection. Pigs fed S-DDGS had less (P < 0.05) SID of histidine, isoleucine, leucine, and methionine compared with those fed T-DDGS, which were less (P < 0.05) than the values observed for pigs fed C-DDGS. The SID of arginine, phenylalanine, threonine, and valine in C-DDGS were greater (P < 0.05) than in S-DDGS but were not different from those in T-DDGS. The SID of lysine in C-DDGS was greater (P < 0.05) than in S-DDGS and T-DDGS. In conclusion, AA in S-DDGS were less digestible than those in C-DDGS and T-DDGS.

Interactive association between processing induced molecular structure changes and nutrient delivery on a molecular basis, revealed by cutting-edge vibrational biomolecular spectroscopy

Background

This study was conducted to determine protein molecular structure profiles and quantify the relationship between protein structural features and protein metabolism and bioavailability of blend pelleted products (BPP) based on co-products (canola or carinata) from processing with different proportions of pulse pea screenings and lignosulfonate chemical compound.

Method

The protein molecular structures were determined using the non-invasive advanced vibrational molecular spectroscopy (ATR-FT/IR) in terms of chemical structure and biofunctional groups of amides (I and II), α-helix and β-sheet.

Results

The results showed that increasing the level of the co-products in BPP significantly increased the spectral intensity of the amide area and amide height. The products exhibited similar protein secondary α-helix to β-sheet ratio. The protein molecular structure profiles (amides I and II, α-helix to β-sheet) were highly associated with protein degradation kinetics and intestinal digestion. In conclusion, the non-invasive vibrational molecular spectroscopy (ATR-FT/IR) could be used to detect inherent structural make-up characteristics in BPP.

Conclusion

The molecular structural features related to protein biopolymer were highly associated with protein utilization and metabolism.

Detect molecular spectral features of newly developed Vicia faba varieties and protein metabolic characteristics in ruminant system using advanced synchrotron radiation based infrared microspectroscopy: A preliminary study

Recently, advanced synchrotron radiation-based Fourier transform infrared microspectroscopy (SR-IMS) has been developed as a rapid, direct, non-destructive and bioanalytical technique. To date, there has been very little application of this technique to study the molecular structure make-up in pulse seeds. Thus, the objectives of this study were to detect the interactive association between protein molecular structure and nutrient availability of newly developed Vicia faba varieties. Two different varieties of faba beans (CDC Snowdrop = low-tannin variety; vs. FB9-4 = high-tannin variety) were selected for this study. The molecular spectra data were collected by using SR-IMS. The ratio of both amide I to II area and height were higher (P < 0.01), while the ratio of α-helix to β-sheet was lower (P < 0.05) in CDC Snowdrop compared to FB9-4. The crude protein (CP) content and the predicted truly digestible nutrients as well as the bioenergy values did not vary between two varieties. The CDC Snowdrop had exhibited a higher (P < 0.01) rapidly degradable CP fraction (75.99 vs. 71.45% on CP) and a lower (P < 0.01) moderately degradable CP fraction (19.43 vs. 22.85% on CP), resulting in a higher (P < 0.01) rumen degradable protein and a lower (P < 0.01) rumen undegradable protein content than that of FB9-4 variety. However, the total supply of digestible rumen undegraded feed protein was higher (P < 0.05) in FB9-4 than CDC Snowdrop. Strong positive correlations were found between the ratio of α-helix to β-sheet and CP contents (R = 0.86, P < 0.01) as well as the truly digestible CP contents (R = 0.83, P < 0.01); respectively. In conclusion, the results of this study reveal that the protein are metabolized differently between different type of faba bean varieties and the advanced SR-IMS molecular spectroscopy can be used to rapidly delineate protein molecular structure motifs along with their nutritive value in ruminant livestock system.

In situ and in vitro evaluation of crude protein degradation and utilisable crude protein content of barley, rye and triticale grains for ruminants

Rations for dairy cows are comprised of high proportions of cereal grains. Thus, despite their low crude protein (CP) content, grains can contribute considerably to the CP intake of dairy cows. This study was conducted to describe and compare ruminal CP degradation of a broad range of barley, rye and triticale genotypes in situ and in vitro and different methods to estimate the utilisable CP at the duodenum (uCP). Twenty samples each of rye, barley and triticale were incubated in situ and in vitro. Exponential regression analyses were used to estimate in situ degradation parameters. Further, the effective degradability (ED), ruminal undegraded CP (UDP) and uCP for ruminal passage rates of 5% and 8% per hr were estimated. The uCP was estimated in vitro and based on two different approaches using in situ UDP data and estimates of microbial synthesised protein (based on fermented organic matter [fOM] or equations of the Gesellschaft für Ernährungsphysiologie). The degradation rate declined from rye (43% per hr) to triticale (27% per hr) to barley (20% per hr), and it exhibited remarkable variation between the genotypes of a single species. The maximal degradable CP fraction also differed between the species, but was overall very high (94%-99%). The lowest washout fraction (26%) and the highest variation in ED (77%-86% and 69%-80% for a passage rate of 5% and 8% per hr, respectively) were found in barley. The in situ uCP content (estimated using fOM) was lower for barley than for rye and triticale at ruminal passage rates of 5% and 8% per hr (barley: 157 g/kg DM at both passage rates; rye and triticale: 168 (at 5% per hr) and 169 (at 8% per hr) g/kg DM). In vitro estimations of uCP did not differ between the grain species and uCP estimated according to GfE was higher for triticale than for barley and rye, which did not differ. The low variation within a single grain species and the weak correlations between ruminal CP degradation and nutrient concentrations suggested that differentiation of ED and uCP between the genotypes of a single grain species is not necessary.

In situ and in vitro ruminal starch degradation of grains from different rye, triticale and barley genotypes

In recent years, advances in plant breeding were achieved, which potentially led to modified nutritional values of cereal grains. The present study was conducted in order to obtain a broad overview of ruminal digestion kinetics of rye, triticale and barley grains, and to highlight differences between the grain species. In total, 20 genotypes of each grain species were investigated using in situ and in vitro methods. Samples were ground (2 mm), weighed into polyester bags, and incubated in situ 1 to 48 h in three ruminally cannulated lactating dairy cows. The in vitro gas production of ground samples (1 mm) was measured according to the 'Hohenheim Gas Test', and cumulative gas production was recorded over different time spans for up to 72 h. There were significant differences (P<0.05) between the species for most parameters used to describe the in situ degradation of starch (ST) and dry matter (DM). The in situ degradation rate (c) and effective degradability (assuming a passage rate of 8%/h; ED8) of ST differed significantly between all grains and was highest for rye (rye: 116.5%/h and 96.2%; triticale: 85.1%/h and 95.0%; barley: 36.2%/h and 90.0% for c and ED8, respectively). With respect to DM degradation, the ranking of the species was similar, and predicted c values exhibited the highest variation within species. The in vitro gas production rate was significantly higher (P<0.05) for rye than for triticale and barley (rye: 12.5%/h; triticale: 11.5%/h; barley: 11.1%/h). A positive relationship between the potential gas production in vitro and the maximal degradable DM fraction in situ was found using all samples (r=0.84; P<0.001) as well as rye (P=0.002) and barley (P<0.001) alone, but not for triticale. Variation in ruminal in situ degradation parameters within the grain species resulted from the high c values, but was not reflected in the ED estimates. Therefore, the usage of mean values for the ED of DM and ST for each species appears reasonable. Estimated metabolisable energy concentrations (ME, MJ/kg DM) and the estimated digestibility of organic matter (dOM, %) were significantly lower (P<0.05) for barley than for rye and triticale. Rye and triticale dOM and ME values were not significantly different (P=0.386 and 0.485).

Structural changes on a molecular basis of canola meal by conditioning temperature and time during pelleting process in relation to physiochemical (energy and protein) properties relevant to ruminants

The objectives of this study were: (1) To investigate the effects of conditioning temperature (70, 80, 90°C), time (30, 60 sec), and interaction (temperature × time) during the pelleting process on internal protein molecular structure changes of the co-products; (2) To identify differences in protein molecular structures among pellets that were processed under different conditions, and between unprocessed mash and pellets; 3) To quantify protein molecular structure changes in relation to predicted energy and protein utilization in dairy cows. The final goal of this program was to show how processing conditions changed internal feed structure on a molecular basis and how molecular structure changes induced by feed processing affected feed milk value in dairy cows. The hypothesis in this study was that processing-induced protein inherent structure changes affected energy and protein availability in dairy cattle and the sensitivity and response of protein internal structure to the different pelleting process conditions could be detected by advanced molecular spectroscopy. The protein molecular structures, amides I and II, amide I to II ratios, α-helix structure, β-sheet structure, and α to β structure ratios, were determined using the advanced vibrational molecular spectroscopy (ATR-FT/IR). The energy values were determined using NRC2001 summary approach in terms of total digestible nutrients, metabolizable and net energy for lactation. The protein and carbohydrate subfactions that are related to rumen degradation characteristics and rumen undegraded protein supply were determined using updated CNCPS system. The experiment design was a RCBD and the treatment design was a 3x2 factorial design. The results showed that pelleting induced changes in protein molecular structure. The sensitivity and response of protein inherent structure to the pelleting depended on the conditioning temperature and time. The protein molecular structure changes were correlated (P < 0.05) with energy values and protein subfractions of the pelleted co-product. The results indicated that the protein internal molecular structure had significant roles in determining energy and protein nutritive values in dairy cows. Multi-regression study with model variables selection showed that the energy and protein profiles in pelleted co-products could be predicted with the protein molecular structure profiles. This approach provides us a relatively new way to estimate protein value in dairy cows based on internal protein molecular structure profile.

Truly Absorbed Microbial Protein Synthesis, Rumen Bypass Protein, Endogenous Protein, and Total Metabolizable Protein from Starchy and Protein-Rich Raw Materials: Model Comparison and Predictions

This study was carried out to measure truly absorbed microbial protein synthesis, rumen bypass protein, and endogenous protein loss, as well as total metabolizable protein, from starchy and protein-rich raw feed materials with model comparisons. Predictions by the DVE2010 system as a more mechanistic model were compared with those of two other models, DVE1994 and NRC-2001, that are frequently used in common international feeding practice. DVE1994 predictions for intestinally digestible rumen undegradable protein (ARUP) for starchy concentrates were higher (27 vs 18 g/kg DM, p < 0.05, SEM = 1.2) than predictions by the NRC-2001, whereas there was no difference in predictions for ARUP from protein concentrates among the three models. DVE2010 and NRC-2001 had highest estimations of intestinally digestible microbial protein for starchy (92 g/kg DM in DVE2010 vs 46 g/kg DM in NRC-2001 and 67 g/kg DM in DVE1994, p < 0.05 SEM = 4) and protein concentrates (69 g/kg DM in NRC-2001 vs 31 g/kg DM in DVE1994 and 49 g/kg DM in DVE2010, p < 0.05 SEM = 4), respectively. Potential protein supplies predicted by tested models from starchy and protein concentrates are widely different, and comparable direct measurements are needed to evaluate the actual ability of different models to predict the potential protein supply to dairy cows from different feedstuffs.

Molecular spectroscopic investigation on fractionation-induced changes on biomacromolecule of co-products from bioethanol processing to explore protein metabolism in ruminants

Fractionation processing is an efficient technology which is capable to redesign/redevelop a new food or feed product with a specified chemical and nutrient profile. This processing technique was able to produce four different fractions (called "A", "B", "C", "D" fractions/treatments) with different nutrient profile form a co-product of bioethanol processing [wheat dried distillers grains with soluble (DDGS)]. To date, there is no study on the effect of fractionation processing on inherent molecular structure of different fractions and how the processing-induced structural change affect the metabolic characteristics of protein and nutrient availability. The objectives of this experiment were to: (1) investigate the effect of fractionation processing on changes of protein functional groups (amide I, amide II, and their ratio) and molecular structure (modeled α-helix, β-sheet, and their ratio), and (2) study the relationship between the fractionation processing-induced changes of protein molecular structure and nutrients availability as well as the metabolic characteristics of protein. The hypothesis of this study was that the fractionation processing changes the molecular structure and such changes affect the metabolic characteristics of protein. The protein molecular structure spectral profile of the fractions A, B, C and D were identified by Fourier-transform infrared attenuated total reflection spectroscopy (FT/IR-ATR). The results showed that the fractionation processing significantly affected the protein molecular spectral profiles. The differences in amide I to amide II peak area and height ratios were strongly significant (P<0.01) among the treatment fractions, ranging from 4.98 to 6.33 and 3.28 to 4.00, respectively. The difference in the modeled protein α-helix to β-sheet ratio was also strongly significant (P<0.01) among the treatment fractions. Multivariate molecular spectral analysis with cluster (CLA) and principal component analyses (PCA) showed that there are no clear distinguished clusters and ellipses among the fractions (A, B, C and D) in the protein amide I and II region ca. 1726-1485 cm(-1). The correlation study showed that the modeled α-helix to β-sheet ratio tended to have a negative correlation with truly absorbed rumen undegraded protein (ARUP(DVE): r=-0.944, P=0.056<0.10) and total truly absorbed protein in the small intestine (DVE: r=-0.946, P=0.054<0.10), but there was no correlation between the α-helix to β-sheet ratio and the degraded protein balance (DPB(OEB): P=0.267<0.10). In conclusion, the fractionation processing changed the molecular structural spectral profiles in terms of amide I to II ratio and α-helix to β-sheet ratio. These changes negatively affected the metabolic characteristics of protein and true protein supply. These results indicated that spectral features of different fractions could be used as a potential tool to predict true protein nutritive value.

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.

Using synchrotron radiation-based infrared microspectroscopy to reveal microchemical structure characterization: frost damaged wheat vs. normal wheat

This study was conducted to compare: (1) protein chemical characteristics, including the amide I and II region, as well as protein secondary structure; and (2) carbohydrate internal structure and functional groups spectral intensities between the frost damaged wheat and normal wheat using synchrotron radiation-based Fourier transform infrared microspectroscopy (SR-FTIRM). Fingerprint regions of specific interest in our study involved protein and carbohydrate functional group band assignments, including protein amide I and II (ca. 1774-1475 cm(-1)), structural carbohydrates (SCHO, ca. 1498-1176 cm(-1)), cellulosic compounds (CELC, ca. 1295-1176 cm(-1)), total carbohydrates (CHO, ca. 1191-906 cm(-1)) and non-structural carbohydrates (NSCHO, ca. 954-809 cm(-1)). The results showed that frost did cause variations in spectral profiles in wheat grains. Compared with healthy wheat grains, frost damaged wheat had significantly lower (p < 0.05) spectral intensities in height and area ratios of amide I to II and almost all the spectral parameters of carbohydrate-related functional groups, including SCHO, CHO and NSCHO. Furthermore, the height ratio of protein amide I to the third peak of CHO and the area ratios of protein amide (amide I + II) to carbohydrate compounds (CHO and SCHO) were also changed (p < 0.05) in damaged wheat grains. It was concluded that the SR-FTIR microspectroscopic technique was able to examine inherent molecular structure features at an ultra-spatial resolution (10 × 10 μm) between different wheat grains samples. The structural characterization of wheat was influenced by climate conditions, such as frost damage, and these structural variations might be a major reason for the decreases in nutritive values, nutrients availability and milling and baking quality in wheat grains.

Synchrotron-based microspectroscopic study on the effects of heat treatments on cotyledon tissues in yellow-type canola (Brassica) seeds

Synchrotron-based infrared (IR) microspectroscopy is able to reveal structural features of biomaterials within intact tissue at both cellular and molecular levels. Heat-related treatments have been used to improve nutrient availability of canola seeds and meal. However, hitherto, there has been no study on the sensitivity and response of each layer in canola seeds to heat-related treatments. It is not known which layer (epiderm/mucllage, spermoderm, endosperm, or cotyledon) is the most sensitive to heat when heat treatment is applied to the seeds. Traditional wet chemical analysis is unable to answer such questions. The objective of this study is to use synchrotron IR microspectroscopy with multivariate molecular spectral analyses as a research tool to study heat treatment effects in a fast way on the structural changes in cotyledon tissues of yellow-type canola (Brassica) seeds among raw (treatment code "A"), wet heating (autoclaving at 121 °C for 60 min, treatment code "B"), and dry heating (dry roasting at 120 °C for 60 min, treatment code "C"). The hypothesis of this study was that different heat treatments have different heat penetration abilities on cotyledon tissues in yellow-type canola seeds. The multivariate analytical tools principal component analysis (PCA) and agglomerative hierarchal cluster analysis (AHCA) were applied to investigate variance and groupings within the spectral data set [whole spectral range of ca. 4000-650 cm(-1), spectral range of ca. 1300-900 cm(-1) (cellulose or saccarides), spectral range of ca. 1800-1500 cm(-1) (secondary structures of protein) and spectral range of ca. 1500-1300 cm(-1) (bending motion of methylene and methyl group; this change is consistent with the change in the range of ca. 3000-2800 cm(-1))]. The results showed that there were no clear cluster and groups formed in the cotyledon tissues among the three treatments (A, B, and C). There were no clear distinguished responses of the cotyledon tissues to different types of heat treatments using multivariate molecular spectral analyses. The results indicate that the cotyledon tissues might not be sufficiently penetrated by both heat treatments (autoclaving and dry roasting) under the specified conditions. A future study is needed to analyze individual functional group band intensity among the treatments using univariate molecular spectral analysis to confirm multivariate PCA and cluster analyses.

What makes protein indigestible from tissue-related, cellular, and molecular aspects?

This paper gives an insight into key factors, which impair enzymatic protein digestion. By nature, some proteins in raw products are already poorly digestible because of structural peculiarities, or due to their occurrence in plant cytoplasmic organelles or in cell membranes. In plant-based protein, molecular and structural changes can be induced by genetic engineering, even if protein is not a target compound class of the genetic modification. Other proteins only become difficult to digest due to changes that occur during the processing of proteinaceous products, such as extruding, boiling, or acidic or alkaline treatment. The utilization of proteinaceous raw materials in industrial fermentations can also have negative impacts on protein digestibility, when reused as fermentation by-products for animal nutrition, such as brewers' grains. After consumption, protein digestion can be impeded in the intestine by the presence of antinutritional factors, which are ingested together with the food or feedstuff. It is concluded that the encircling matrix, but also molecular, chemical, and structural peculiarities or modifications to amino acids and proteins obstruct protein digestion by common proteolytic enzymes in humans and animals.