Metabolic characteristics in ruminants of the proteins in newly developed hull-less barley varieties with altered starch traits

Effect of Whole Grain Qingke (Tibetan Hordeum vulgare L. Zangqing 320) on the Serum Lipid Levels and Intestinal Microbiota of Rats under High-Fat Diet

This study investigated the hypolipidemic effect of whole grain Qingke (WGQ) and its influence on intestinal microbiota. Changes in the serum lipid, intestinal environment, and microbiota of Sprague-Dawley rats fed high-fat diets supplemented with different doses of WGQ were determined. Results showed that high doses of WGQ significantly decreased (P < 0.05) the Lee's index, serum total cholesterol, low-density lipoprotein cholesterol, and non-high-density lipoprotein cholesterol levels whereas they increased the body weight of the rats. Cecal weight and short-chain fatty acid (SCFA) concentration increased with increasing WGQ dose. An Illumina-based sequencing approach showed that the relative abundance of putative SCFA-producing bacteria Prevotella and Anaerovibrio increased in the rats fed the WGQ diet. Principal component analysis revealed a significant difference in intestinal microbiota composition after the administration of the WGQ diet. These findings provide insights into the contribution of the intestinal microbiota to the hypolipidemic effect of WGQ.

The inter-relationship between processing-induced molecular structure features and metabolic and digestive characteristics in hulled and hulless barley (Hordeum vulgare) grains with altered carbohydrate traits

BACKGROUND

The present study aimed to determine the microwave irradiation (MIR)-induced changes in protein molecular structures in barley (Hordeum vulgare) grains in relation to the truly absorbable protein nutrient supply to ruminant livestock systems. Samples from hulled and hulless cultivars of barley, harvested in consecutive years from four replicate plots, were evaluated. The samples were either kept raw or were irradiated with microwaves for 3 min (MIR3) or 5 min (MIR5). The truly absorbable protein nutrient supply to ruminant livestock systems was evaluated using the DVE/OEB system (DVE, truly absorbed protein in the small intestine; OEB, degraded protein balance). Molecular structure changes as a result of processing were revealed by vibrational molecular spectroscopy in the mid-infrared electromagnetic radiation region.

RESULTS

Compared to the raw samples, MIR processing decreased (P < 0.05) the truly absorbable microbial crude protein and increased (P < 0.05) the truly absorbable rumen undegraded protein and endogenous protein supply without affecting the total truly absorbed protein supply to the small intestine (DVE) and degraded protein balance (OEB) in ruminant livestock systems. Changes in protein molecular structure (spectral intensities) were highly correlated with the changes in the truly absorbed protein nutrient supply to ruminant livestock systems.

CONCLUSION

The results of the present study show that the changes in protein molecular structure as a result of MIR feed processing were associated with the truly absorbed protein supply to ruminant livestock systems. © 2016 Society of Chemical Industry.

Microwave irradiation induced changes in protein molecular structures of barley grains: relationship to changes in protein chemical profile, protein subfractions, and digestion in dairy cows

The objectives of this study were to evaluate microwave irradiation (MIR) induced changes in crude protein (CP) subfraction profiles, ruminal CP degradation characteristics and intestinal digestibility of rumen undegraded protein (RUP), and protein molecular structures in barley (Hordeum vulgare) grains. Samples from hulled (n = 1) and hulless cultivars (n = 2) of barley, harvested from four replicate plots in two consecutive years, were evaluated. The samples were either kept as raw or irradiated in a microwave for 3 min (MIR3) or 5 min (MIR5). Compared to raw grains, MIR5 decreased the contents of rapidly degradable CP subfraction (from 45.22 to 6.36% CP) and the ruminal degradation rate (from 8.16 to 3.53%/h) of potentially degradable subfraction. As a consequence, the effective ruminal degradability of CP decreased (from 55.70 to 34.08% CP) and RUP supply (from 43.31 to 65.92% CP) to the postruminal tract increased. The MIR decreased the spectral intensities of amide 1, amide II, α-helix, and β-sheet and increased their ratios. The changes in protein spectral intensities were strongly correlated with the changes in CP subfractions and digestive kinetics. These results show that MIR for a short period (5 min) with a lower energy input can improve the nutritive value and utilization of CP in barely grains.

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.

Metabolic characteristics of the proteins in yellow-seeded and brown-seeded canola meal and presscake in dairy cattle: comparison of three systems (PDI, DVE, and NRC) in nutrient supply and feed milk value (FMV)

To the authors' knowledge, there is little research on metabolic characteristics of the protein in newly developed yellow and brown types of canola meal and canola presscake. The objectives of this study were to (1) identify differences in the metabolic characteristics of the protein among yellow-seeded ( Brassica juncea ) and brown-seeded ( Brassica napus ) canola meal and brown-seeded (B. napus) canola presscake modeled for dairy cattle, (2) determine the extent of ruminal and intestinal digestion and absorption of the protein, (3) determine feed milk value, and (4) compare three evaluation systems in modeling nutrient supply to dairy cattle, namely, the DVE/OEB system (DVE, truly absorbed protein in the small intestine; OEB, degraded protein balance), the National Research Council (NRC) 2001 model, and the PDI system (protein truly digestible in the small intestine). Comparison was made in terms of (1) ruminally synthesized microbial protein, (2) truly absorbed protein in the small intestine, (3) endogenous protein, (4) total metabolizable protein, and (5) degraded protein balance. The results showed that there were significant differences in the truly absorbed protein supply, protein degraded balance, and feed milk value (P < 0.05) among the different types of canola meal. Yellow-seeded canola meal had significantly higher (P < 0.05) intestinal digestibility of rumen undegraded crude protein (%dRUP) than brown-seeded canola meal and presscake (%dRUP, 90 vs 75 and 60%, respectively). Yellow-seeded canola meal also had higher (P < 0.05) total metabolizable protein predicted by all three models (DVE, 312 vs 192 and 128 g/kg DM; MP, 287 vs 193 and 168 g/kg DM; PDIA, 264 vs 168 and 137 g/kg DM, respectively), lower (P < 0.05) degraded protein balance (OEB, 84 vs 104 and 102 g/kg DM; DPB, 49 vs 60 and 57 g/kg DM, respectively), and higher (P < 0.05) feed milk value (6.3 vs 3.9 and 2.6 kg milk/kg feed, respectively) than the brown-seeded canola meal and presscake. In the model comparison, the supply of endogenous protein predicted by the DVE/OEB system was higher (P < 0.05) than that predicted by the NRC-2001 model. Moreover, a high proportion of the variability in truly absorbed rumen-undegraded feed protein in the small intestine and the total metabolizable protein predicted by the DVE/OEB system was found that can be accounted for by the equivalent parameters predicted by the NRC-2001 model. The truly absorbed rumen-synthesized microbial protein values predicted from the PDI system were 19% lower than those predicted from the DVE/OEB system. Between the two latest mentioned models, no differences were detected in truly absorbed rumen-undegraded feed protein, microbial protein supply based on available energy, and degraded protein balance. All of the parameters predicted by the PDI system can be accounted for by the equivalent parameters predicted by the DVE/OEB system. When the PDI system and NRC-2001 model were compared, the overall means for microbial protein supply based on energy and truly absorbed rumen-synthesized microbial protein were found to be lower than those predicted by the NRC-2001 model. Although the factors used in quantifying calculations as well as the evaluation system's concepts differ among each other, all three protein evaluation systems employed in this study efficiently predict the potential nutrient supply to the animal from feedstuffs as affected by processing. In conclusion, the yellow-seeded canola meal provided the highest total metabolizable protein and the lowest degraded protein balance.