Site Of Digestion Research Articles

Granulated Cane Sugar as a Partial Replacement for Steam-Flaked Corn in Diets for Feedlot Cattle: Ruminal Fermentation and Microbial Protein Synthesis

The aim of this study was to evaluate the influence of supplemental granulated cane sugar (GCS) levels (0, 13.3, 26.6, and 39.9% on a dry matter basis) in a steam-flaked corn-based finishing diet on measures of ruminal fermentation and the site and extent of nutrient digestion. Four Holstein steers (251 ± 3.6 kg live weight) with “T” type cannulas in the rumen and proximal duodenum were used in a 4 × 4 Latin square experiment to evaluate the treatments. The experiment lasted 84 d. Replacing steam-flaked corn (SFC) with GCS linearly decreased the flow of ammonia-N (NH3-N) to the small intestine, increasing the flow of microbial nitrogen (MN; quadratic effect, p = 0.02), ruminal N efficiency (linear effect, p = 0.03) and MN efficiency (quadratic effect, p = 0.04). The ruminal digestion of starch and neutral detergent fiber (NDF) decreased (linear effect, p ≤ 0.02) as the level of GCS increased. The postruminal digestion of organic matter (OM), neutral detergent fiber (NDF), and starch were not affected by the GCS inclusion. However, postruminal N digestion decreased (linear effect, p = 0.02) as the level of GCS increased. There were no treatment effects on total tract OM digestion. However, total tract NDF and N digestion decreased (linear effect, p ≤ 0.02) as the level of GCS increased. The ruminal pH decreased (linear effect, p < 0.01) as the GCS increased in the diet. The ruminal acetate molar proportion decreased (linear effect, p = 0.02) and the ruminal valerate molar proportion tended to increase (linear effect, p = 0.08) as the level of GCS increased. It is concluded that replacing as much as 13% of SFC with GCS in a finishing diet will enhance the efficiency of N utilization (g non-ammonia-N entering the small intestine/g N intake) without detrimental effects on total tract OM digestion. The inclusion of GCS decreased the ruminal proportion of acetate linearly without an effect on the acetate-to-propionate ratio or estimated methane production. Some of the effects on N utilization at a high level of GCS inclusion (27 and 40%) can be magnified by the differences in the CP content between diets. A higher level of GCS supplementation in the diet decreased the ruminal pH below 5.5, increasing the risk of ruminal acidosis.

MDS-407 High Risk Myelodysplastic Syndrome

Myelodysplastic syndromes are characterized by a frequent evolution into acute leukemia. Research has made it possible to better understand their physiopathology, and have made advances in classification, prognosis and treatment. The main objective of our study is to determine the incidence of high-risk myelodysplastic syndromes in the general population in Morocco. Patients diagnosed with MDS classified as high risk by the IPSS score between January 2004 and December 2018. We data on collected 34 patients with high-risk MDS, the average frequency of cases per year was 2.5 cases, the median age is 59.5 years, the sex ratio is 0.74. 1% of patients were genetically predisposed, 16% of patients with occupational and environmental exposure. Clinically the main symptoms of the disease were anemia, hemorrhage, and infectious syndrome. The median time between the onset of symptoms and the date of diagnosis is 3 months. The infectious sites concerned were the ENT site, the urinary site, the digestive site, and the pulmonary site. According to the IPSS-R: According to the IPSS, patients at high risk are young adults (n=9), elderly subjects (n=4), and very elderly subjects (n=4). Patients with high or very high risk IPSS-R have median survival times of 4.61 and 4.4 months, respectively. 74% of cases received symptomatic treatment, 6.5% of cases received specific treatment with azacitidine, and 3% of cases received chemotherapy based on cytarabine. The disease was stable in 70.5% (n=24) of the cases, whereas 29.5% (n=10) of the cases transformed into acute leukemia. The median time between the date of diagnosis and the date of transformation into AML is 3 months, with extremes ranging from 32 to 270 days. The number of deaths is 32% (n=11); median survival is 4 months. Our results agree with the studies published in the literature with regard to epidemiology, incidence, clinic, prognosis, and symptomatic treatment, but there are some discrepancies in terms of specific treatment and global survival. Myelodysplastic syndromes remain a serious problem that threatens the health of patients. The main complication detected in our series was transformation into acute leukemia.

388 Young Scholar Award Talk: Increasing Efficiency of Finishing Beef Production: Optimizing Starch Digestion, Improving Flaking Quality, and Reducing Methane Emissions

Abstract The objectives of my dissertation research are to develop strategies to increase the efficiency of finishing beef production by optimizing the site and extent of starch digestion, improving flaking quality and consistency, and reducing methane emissions. Post-flaking sampling and handling techniques such as sifting steam-flaked corn samples with a sieve (P < 0.01), air equilibration time (P < 0.01), and storage temperature during shipping (P < 0.01) all influenced enzymatic starch availability of steam-flaked corn. Inducing starch retrogradation of steam-flaked corn decreased the rate (P < 0.01), but not the extent (P = 0.80), of ruminal dry matter degradation and thus, energetic efficiency was predicted to increase by up to 3.4% because of increased postruminal flow and digestion of starch in the small intestine. If producing steam-flaked corn is not feasible for smaller capacity feedlots, finely ground corn has a similar ruminal starch solubility to steamflaked corn (38.1% vs. 44.4, respectively, P > 0.05), suggesting an alternative processing method to increase feeding value in finishing diets. Duodenal infusion of glucoamylase (fungal origin) increased (P = 0.02) small intestinal starch disappearance in steers, while duodenal infusion of porcine α-amylase did not (P = 0.41), supporting the hypothesis that small intestinal carbohydrases are the primary hydrolytic limit to small intestinal starch digestion. Comparative sequencing analyses revealed a missing region of the stalk region of the sucrase-isomaltase protein sequence (AA 47-60) which is important for intracellular sorting of the sucrase subunit to the apical membrane. The absence of this region of the protein likely explains the absence of intestinal sucrase activity and quantitative limitations of starch digestion in the ruminant small intestine. Feeding decoquinate with Yucca schidigera extract for 7-d decreased (P < 0.01) ruminal acetate proportion and tended to increase ruminal (P = 0.08) propionate proportion, suggesting potential for hydrogen shifts which could contribute to reductions in methane emissions with longer feeding periods. The findings of my dissertation research provide: 1) post-flaking sampling and handling recommendations for commercial feedlots and laboratories to improve estimates of starch availability and flaking consistency, 2) a mechanistic target (sucrase-isomaltase) for limitations in small intestinal starch digestion, 3) practical feeding strategies to shift the site of starch digestion to the small intestine to increase feed efficiency (retrogradation), 4) new processing alternatives for small feedlot producers (fine ground corn inclusion), and 5) new information on how combinations of feed additives could potentially decrease methane production in feedlot cattle.

Human Hepatic Transporter Signature Peptides for Quantitative Targeted Absolute Proteomics: Selection, Digestion Efficiency, and Peptide Stability.

Quantitative targeted absolute proteomics (QTAP) quantifies proteins by measuring the signature peptides produced from target proteins by trypsin digestion. The selection of signature peptides is critical for reliable peptide quantification. The purpose of this study was to comprehensively assess the digestion efficiency and stability of tryptic peptides and to identify optimal signature peptides for human hepatic transporters and membrane marker proteins. The plasma membrane fraction of the human liver was digested at different time points and the peptides were comprehensively quantified using quantitative proteomics. Transporters and membrane markers were quantified using the signature peptides by QTAP. Tryptic peptides were classified into clusters with low digestion efficiency, low stability, and high digestion efficiency and stability. Using the cluster information, we found that a proline residue next to the digestion site or the peptide position in or close to the transmembrane domains lowers digestion efficiency. A peptide containing cysteine at the N-terminus or arginine-glycine lowers peptide stability. Based on this information and the time course of peptide quantification, optimal signature peptides were identified for human hepatic transporters and membrane markers. The quantification of transporters with multiple signature peptides yielded consistent absolute values with less than 30% of coefficient variants in human liver microsomes and homogenates. The signature peptides selected in the present study enabled the reliable quantification of human hepatic transporters. The QTAP protocol using these optimal signature peptides provides quantitative data on hepatic transporters usable for integrated pharmacokinetic studies.

The effect of lactulose thermal degradation products on β-lactoglobulin: Linear-, loop-, and cross-link structural modifications and reduced digestibility

The thermal degradation products of lactulose and the interaction between lactulose and β-lactoglobulin (βLg) were investigated in a thermal model system. Lactulose was thermally degraded into fructose and galactose, which were further degraded into methylglyoxal, glyoxal, 3-deoxyglucosone, and 2, 3-butanedione via heating. After incubating with lactulose, the structure of βLg was changed, which manifested by the formation of new band with doubled the molecular weight of βLg in the mobility spectrum and the changes in the internal fluorescence spectrum. Furthermore, the lysine and arginine residues of βLg were confirmed to be the modification sites of the thermal degradation products of lactulose, and the modification types of linear-, loop-, and cross-linked were detected. The digestibility of βLg incubated with lactulose was significantly decreased due to the modification of trypsin digestion sites and the formation of cross-linked conjunctions. Therefore, the adverse effects of lactulose application in thermally processed foods should be concerned.

Prevalence of chronic obstructive pulmonary disease among 48,061 digestive tract cancer patients in Europe

Chronic obstructive pulmonary disease (COPD) shares common risk factors with digestive tract malignancies such as esophageal cancer. However, the prevalence and geographic distribution of COPD in patients with gastrointestinal (GI) cancer is only poorly understood. We used the IQVIA's Oncology Dynamics (OD) database to identify a total of 48,061 patients with GI cancer (4,229 esophagus, 7,568 stomach, 27,300 colon, and 8,964 rectum cancer) from Germany, France, Italy, Spain and the UK. The prevalence of COPD among the 48,061 patients with GI cancer was 12.5% (5,983/48,061). We observed significant differences in frequencies of COPD between the different cancer sites with the highest COPD prevalence among patients with esophageal (25.5%) or gastric cancer (13.4%) and lowest prevalence in colon (11.0%) or rectal (9.8%) cancer patients. Moreover, rates of COPD strongly varied between digestive tract cancer patients from different countries. Interestingly, Spain (16.8%) and Germany (13.4%) had the highest COPD prevalence while prevalence of COPD was lowest in the UK (8.4%). Finally, we showed that the proportion of digestive tract cancer patients with COPD was highest among male patients (15%) and those >80 years (20.6%) when compared to all other patients. In this analysis, we show that COPD is found at high frequencies in patients with digestive tract cancer in Europe. We demonstrate that prevalence varies according to digestive tract cancer sites and European countries.

Effect of Fiber Fermentation and Protein Digestion Kinetics on Mineral Digestion in Pigs.

Simple SummaryThere is increasing interest in improving nutrient utilization in pigs and poultry and thereby reduce nutrient excretion into the environment. The present review aims to provide an overview on interactions between fermentable substrates (e.g., starch, fiber, and protein) and selected minerals on nutrient digestion and absorption to determine nutritional solutions to maximize animal performance, principally in the grower–finisher phase. Using in vitro models, the site and rate (kinetics) of nutrient digestion or fermentation of a feed ingredient or diet can be estimated. However, for minerals, no standardized methodology to assess in vitro mineral digestion exists. In vivo, the diet total tract digestibility of phosphorus might be underestimated in diets with fermentable ingredients because of increased diet-specific endogenous phosphorus losses and requires further clarification to better calculate the true total tract digestibility of phosphorus in pigs. The quantification of fiber type, composition of fiber fractions within individual raw materials, their influence on digestion kinetics, and effects on digesta pH and nutrient solubility related to fermentation should be considered. In conclusion, applications of nutrient kinetic data should be considered as part of an integrated approach to support nutrient digestion and absorption in the gastrointestinal tract of pigs, thereby helping to reduce nutrient excretion.Nutrient kinetic data and the timing of nutrient release along the gastrointestinal tract (GIT), are not yet widely used in current feed formulations for pigs and poultry. The present review focuses on interactions between fermentable substrates (e.g., starch, fiber, and protein) and selected minerals on nutrient digestion and absorption to determine nutritional solutions to maximize animal performance, principally in the grower–finisher phase, with the aim of minimizing environmental pollution. For phosphorus (P), myo-inositol 1,2,3,4,5,6-hexakis (dihydrogen phosphate) (InsP6), copper (Cu), and zinc (Zn), no standardized methodologies to assess in vitro mineral digestion exist. The stepwise degradation of InsP6 to lower inositol phosphate (InsP) forms in the GIT is rare, and inositol phosphate4 (InsP4) might be the limiting isomer of InsP degradation in diets with exogenous phytase. Furthermore, dietary coefficients of standardized total tract digestibility (CSTTD) of P might be underestimated in diets with fermentable ingredients because of increased diet-specific endogenous P losses (EPL), and further clarification is required to better calculate the coefficients of true total tract digestibility (CTTTD) of P. The quantification of fiber type, composition of fiber fractions, their influence on digestion kinetics, effects on digesta pH, and nutrient solubility related to fermentation should be considered for formulating diets. In conclusion, applications of nutrient kinetic data should be considered to help enhance nutrient digestion and absorption in the GIT, thereby reducing nutrient excretion.

An emerging role of vitamin D3 in amino acid absorption in different intestinal segments of on-growing grass carp (Ctenopharyngodon idella).

Vitamin D3 (VD3), an essential nutrient for animals, has been demonstrated to stimulate the uptake of certain amino acids. However, the role of VD3 in the intestine, the primary site for digestion and absorption of nutrients, remains poorly characterized. Here, the grass carp (Ctenopharyngodon idella) was studied to assess the influence of different doses of VD3 (15.2, 364.3, 782.5, 1,167.9, 1,573.8, and 1,980.1 IU/kg) on growth performance, intestinal morphology, digestive absorption, amino acid transport, and potential signaling molecule levels in a feeding experiment. As a result, dietary VD3 improved growth performance, intestinal structure, and digestive and brush border enzyme activities. Additionally, most intestinal free amino acids and their transporters were upregulated after VD3 intake, except for Ala, Lys, Asp, Leu, solute carrier (SLC) 7A7, SLC1A5, and SLC1A3 mRNA in different segments, Leu and SLC6A14 mRNA in the proximal intestine, and SLC7A5 mRNA in the mid and distal intestine. In the crucial target of rapamycin (TOR) signal pathway of amino acid transport, the gene and protein expression of TOR, S6 kinase 1, and activating transcription factor 4 were elevated, whereas 4E-binding protein 1 was decreased, further suggesting an advanced amino acid absorption capacity in the fish due to VD3 supplementation. Based on percentage weight gain, feed efficiency, and trypsin activity, the VD3 requirements of on-growing grass carp were estimated to be 968.33, 1,005.00, and 1,166.67 IU/kg, respectively. Our findings provide novel recommendations for VD3 supplementation to promote digestion and absorption capacities of fish, contributing to the overall productivity of aquaculture.

Small Intestine Microbiome and Metabolome of High and Low Residual Feed Intake Angus Heifers.

The gastrointestinal tract (GIT) contains complex microbial communities and plays an essential role in the overall health of the host. Previous studies of beef cattle feed efficiency have primarily concentrated on the ruminal microbiota because it plays a key role in energy production and nutrient supply in the host. Although the small intestine is the important site of post-ruminal digestion and absorption of nutrients, only a few studies have explored the relationship between the microbial populations in the small intestine and feed efficiency. Moreover, variations in GIT metabolites contribute to differences in feed efficiency. The objective of this study was to investigate relationships among bacterial populations of duodenum, jejunum, ileum; microbial metabolites; and RFI phenotype of beef cattle. We carried out by using Illumina MiSeq sequencing of the 16S rRNA V3-V4 region and liquid chromatography-mass spectrometry (LC–MS). In the duodenum, the relative abundances of Firmicutes ( p < 0.01), Lachnospiraceae, Ruminococcaceae, Family_XIII, Christensenellaceae, Christensenellaceae_R-7_group ( p < 0.05), and Lachnospiraceae_NK3A20_group ( p < 0.05) were higher in the low residual feed intake (LRFI) group compared with the high residual feed intake (HRFI) group, whereas the HRFI group had higher abundances of Proteobacteria and Acinetobacter ( p < 0.01). In the jejunum, the relative abundances of Lachnospiraceae and Lachnospiraceae_NK3A20_group were higher in the LRFI group ( p < 0.05). In the ileum, the relative abundances of Ruminococcaceae ( p < 0.01), Christensenellaceae, Christensenellaceae_R-7_group, and Ruminococcus_2 were also higher in the LRFI group ( p < 0.05). Moreover, the genera Lachnospiraceae_NK3A20_group, Christensenellaceae_R-7_group, and Ruminococcus_2 were negatively associated with RFI, while the genus Acinetobacter was positively associated with RFI. The metabolomics analysis revealed that the LRFI group significantly improved protein digestion and absorption, as well as glycerophospholipid metabolism in the duodenum, jejunum, ileum. The correlation between intestinal microorganisms and metabolites revealed that some microorganisms play an important role in amino acid metabolism, glycerophospholipid metabolism, nutrient digestion and absorption, and antioxidant enhancement. The present study provides a better understanding of the small intestinal microbiota and metabolites of beef cattle with different RFI phenotypes and the relationships among them, which are potentially important for the improvement of beef cattle feed efficiency.

Microscale structural changes of individual fibrin fibers during fibrinolysis

Fibrinolysis is the enzymatic digestion of fibrin, the primary structural component in blood clots. Mechanisms of fibrin fiber digestion during lysis have long been debated and obtaining detailed structural knowledge of these processes is important for developing effective clinical approaches to treat ischemic stroke and pulmonary embolism. Using dynamic fluorescence microscopy, we studied the time-resolved digestion of individual fibrin fibers by the fibrinolytic enzyme plasmin. We found that plasmin molecules digest fibers along their entire lengths, but that the rates of digestion are non-uniform, resulting in cleavage at a single location along the fiber. Using mathematical modeling we estimated the rate of plasmin arrival at the fiber surface and the number of digestion sites on a fiber. We also investigated correlations between local fiber digestion rates, cleavage sites, and fiber properties such as initial thickness. Finally, we uncovered a previously unknown tension-dependent mechanism that pulls fibers apart during digestion. Taken together these results promote a paradigm shift in understanding mechanisms of fibrinolysis and underscore the need to consider fibrin tension when assessing fibrinolytic approaches. Statement of significanceWe developed a method for interrogating lysis of individual fibrin fibers, enabling the time-resolved observation of individual fiber digestion for the first time. Our results resolve longstanding disagreements about fibrinolytic processes and reveal previously unknown mechanisms that also play a role. Also, we developed the first microscale mathematical model of plasmin-fibrin interaction, which predicts the number of plasmin molecules on each fiber and can serve as a framework for investigating novel therapeutics.

Small Intestine-specific Knockout of CIDEC Improves Obesity and Hepatic Steatosis by Inhibiting Synthesis of Phosphatidic Acid.

The small intestine is main site of exogenous lipid digestion and absorption, and it is important for lipid metabolic homeostasis. Cell death-inducing DNA fragmentation-factor like effector C (CIDEC) is active in lipid metabolism in tissues other than those in the intestine. We developed small intestine-specific CIDEC (SI-CIDEC-/-) knockout C57BL/6J mice by Cre/LoxP recombination to investigate the in vivo effects of intestinal CIDEC on lipid metabolism. Eight-week-old SI-CIDEC-/- mice fed a high-fat diet for 14 weeks had 15% lower body weight, 30% less body fat mass, and 79% lower liver triglycerides (TG) than wild-type (WT) mice. In addition, hepatic steatosis and fatty liver inflammation were less severe in knockout mice fed a high-fat diet (HFD) compared with wild-type mice fed an HFD. SI-CIDEC-/- mice fed an HFD diet had lower serum TG and higher fecal TG and intestinal lipase activity than wild-type mice. Mechanistic studies showed that CIDEC accelerated phosphatidic acid synthesis by interacting with 1-acylglycerol-3-phosphate-O-acyltransferase to promote TG accumulation. This study identified a new interacting protein and previously unreported CIDEC mechanisms that revealed its activity in lipid metabolism of the small intestine.

Detection of protease digestion site using fluorescence labeled peptide array and construction of machine-learning prediction model

Detection of protease digestion site using fluorescence labeled peptide array and construction of machine-learning prediction model

Prevalence of diabetes mellitus among 80,193 gastrointestinal cancer patients in five European and three Asian countries

BackgroundDiabetes mellitus (DM) has recently been associated with an increased incidence of such digestive tract malignancies as gastric or colorectal cancer. However, systematic data on the prevalence of DM among digestive tract cancer entities, especially in terms of geographic distributions, are lacking.MethodsWe used the Oncology Dynamics database (IQVIA) to identify a total of 80,193 patients with gastrointestinal (GI) cancer (5845 esophagus, 20,806 stomach, 38,138 colon, and 15,414 rectum cancer patients) from eight European and Asian countries.ResultsThe overall prevalence of DM among all digestive tract cancer patients was 14.8% (11,866/80,193). In terms of cancer site, DM prevalence was highest in patients with colon (15.5%) or rectal (15.3%) cancer and lowest in patients with esophageal cancer (12.0%). Interestingly, we observed significant differences in DM prevalence between countries. Spain (27.8%, 31.3%) and South Korea (21.0%, 27.9%) had the highest prevalence of DM among gastric and colon cancer patients, while DM prevalence in esophageal (18.8%) and rectal (38.0%) cancer patients was highest in Germany.ConclusionOur data revealed a high prevalence of DM among digestive tract cancer patients in Europe and Asia, and showed that DM prevalence varies among digestive tract cancer sites as well as countries.

Pathotyping of Newcastle Disease Virus: a Novel Single BsaHI Digestion Method of Detection and Differentiation of Avirulent Strains (Lentogenic and Mesogenic Vaccine Strains) from Virulent Virus.

ABSTRACTWe provide a novel single restriction enzyme (RE; BsaHI) digestion approach for detecting distinct pathotypes of Newcastle disease virus (NDV). After scanning 4,000 F gene nucleotide sequences in the NCBI database, we discovered a single RE (BsaHI) digestion site in the cleavage site. APMV-I “F gene” class II-specific primer-based reverse transcriptase PCR was utilized to amplify a 535-bp fragment, which was then digested with the RE (BsaHI) for pathotyping avian NDV field isolates and pigeon paramyxovirus-1 isolates. The avirulent (lentogenic and mesogenic strains) produced 189- and 346-bp fragments, respectively, but the result in velogenic strains remained undigested with 535-bp fragments. In addition, 45 field NDV isolates and 8 vaccine strains were used to confirm the approach. The sequence-based analysis also agrees with the data obtained utilizing the single RE (BsaHI) digestion approach. The proposed technique has the potential to distinguish between avirulent and virulent strains in a short time span, making it valuable in NDV surveillance and monitoring research.IMPORTANCE The extensive use of the NDV vaccine strain and the existence of avirulent NDV strains in wild birds makes it difficult to diagnose Newcastle Disease virus (NDV). The intracerebral pathogenicity index (ICPI) and/or sequencing-based identification, which are required to determine virulent NDV, are time-consuming, costly, difficult, and cruel techniques. We evaluated 4,000 F gene nucleotide sequences and discovered a restriction enzyme (RE; BsaHI) digestion technique for detecting NDV and vaccine pathotypes in a short time span, which is cost-effective and useful for field cases as well as for large-scale NDV monitoring and surveillance. The data acquired using the single RE BsaHI digestion technique agree with the sequence-based analysis.

Effect of modifying β-casein by maillard reaction and genipin crosslinking on in vitro digestion of the micelles

β-casein (β-CN) from bovine milk has attracted increasingly interest as biocompatible, non-toxic nano-carrier for hydrophobic functional components due to molecules capable of self-assembly micellar nanostructures. In this study, Maillard reaction and genipin crosslinking were used for modifying β-CN micelles (G-CGDNs) aiming to enhance the stability and achieve a time-release capability as nano-carriers of naringenin. G-CGDNs showed a significant decrease in encapsulation efficiency of naringenin, while the controlled naringenin release properties were enhanced. In vitro studies, the effect of modification on digestibility by pepsin and trypsin were investigated using SDS-PAGE, TEM, DLS, MALDI-TOF-MS and LC-MS/MS. G-CGDNs and genipin crosslinked β-CN micelles loading naringenin (G-CNMs) were all more resistant towards action of the protease hydrolysis. Meanwhile, G-CGDNs digestive products could reassemble into uniform and large spherical micelles in the end of digestion, whereas G-CNMs and β-CN micelles loading naringenin (CNMs) were all damaged to irregular and aggregation or coalescence. Although more compact structure decreased the digestion sites of G-CGDNs to attack by pepsin and trypsin, there was slight change in the release of bioactive peptides. This research can help explore the impact of two modified approaches on β-CN micelles, which will improve stability, maintain nutritional value, and provide a delayed reaction in digestion.

Nutrition and Metabolism: Foundations for Animal Growth, Development, Reproduction, and Health.

Consumption of high-quality animal protein plays an important role in improving human nutrition, growth, development, and health. With an exponential growth of the global population, demands for animal-sourced protein are expected to increase by 60% between 2021 and 2050. In addition to the production of food protein and fiber (wool), animals are useful models for biomedical research to prevent and treat human diseases and serve as bioreactors to produce therapeutic proteins. For a high efficiency to transform low-quality feedstuffs and forages into high-quality protein and highly bioavailable essential minerals in diets of humans, farm animals have dietary requirements for energy, amino acids, lipids, carbohydrates, minerals, vitamins, and water in their life cycles. All nutrients interact with each other to influence the growth, development, and health of mammals, birds, fish, and crustaceans, and adequate nutrition is crucial for preventing and treating their metabolic disorders (including metabolic diseases)and infectious diseases. At the organ level,the small intestine is not only the terminal site for nutrient digestion and absorption, but also intimately interacts with a diverse community of intestinal antigens and bacteria to influence gut and whole-body health. Understanding the species and metabolism of intestinal microbes, as well as their interactions with the intestinal immune systems and the host intestinal epitheliumcan help to mitigate antimicrobial resistanceand develop prebiotic and probiotic alternatives to in-feed antibiotics in animal production. As abundant sources of amino acids, bioactive peptides,energy, and highly bioavailable mineralsand vitamins, animal by-product feedstuffs are effective for improving the growth, development, health, feed efficiency, and survival of livestock and poultry, as well as companion and aquatic animals. The new knowledge covered in this and related volumes of Adv Exp Med Biol is essential to ensure sufficient provision of animal protein for humans, while helping reduce greenhouse gas emissions,minimize the urinary and fecal excretion of nitrogenous and other wastes to the environment, and sustain animal agriculture(including aquaculture).

Plasma membrane N-glycoproteome analysis of wheat seedling leaves under drought stress

Protein glycosylation is one of the ubiquitous post-translational modifications in eukaryotic cells, which play important roles in plant growth and adverse response. In this study, we performed the first comprehensive wheat plasma membrane N-glycoproteome analysis under drought stress via glycopeptide HILIC enrichment and LC-MS/MS identification. In total, 414 glycosylated sites corresponding to 407 glycopeptides and 312 unique glycoproteins were identified, of which 173 plasma membrane glycoproteins with 215 N-glycosylation sites were significantly regulated by drought stress. Functional enrichment analysis reveals that the significantly regulated N-glycosylation proteins were particularly related to protein kinase activity involved in the reception and transduction of extracellular signal and plant cell wall remolding. The motifs and sequence structures analysis showed that the significantly regulated N-glycosylation sites were concentrated within [NxT] motif, and 79.5% of them were located on the random coil that is always on the protein surface and flexible regions, which could facilitate protein glycosylated modification and enhance protein structural stability via reducing protein flexibility. PNGase F enzyme digestion and glycosylation site mutation further indicated that N-glycosylated modification could increase protein stability. Therefore, N-glycosylated modification is involved in plant adaptation to drought stress by improving the stability of cell wall remodeling related plasma membrane proteins.

Characterisation of the enzyme transport path between shipworms and their bacterial symbionts

BackgroundShipworms are marine xylophagus bivalve molluscs, which can live on a diet solely of wood due to their ability to produce plant cell wall-degrading enzymes. Bacterial carbohydrate-active enzymes (CAZymes), synthesised by endosymbionts living in specialised shipworm cells called bacteriocytes and located in the animal’s gills, play an important role in wood digestion in shipworms. However, the main site of lignocellulose digestion within these wood-boring molluscs, which contains both endogenous lignocellulolytic enzymes and prokaryotic enzymes, is the caecum, and the mechanism by which bacterial enzymes reach the distant caecum lumen has remained so far mysterious. Here, we provide a characterisation of the path through which bacterial CAZymes produced in the gills of the shipworm Lyrodus pedicellatus reach the distant caecum to contribute to the digestion of wood.ResultsThrough a combination of transcriptomics, proteomics, X-ray microtomography, electron microscopy studies and in vitro biochemical characterisation, we show that wood-digesting enzymes produced by symbiotic bacteria are localised not only in the gills, but also in the lumen of the food groove, a stream of mucus secreted by gill cells that carries food particles trapped by filter feeding to the mouth. Bacterial CAZymes are also present in the crystalline style and in the caecum of their shipworm host, suggesting a unique pathway by which enzymes involved in a symbiotic interaction are transported to their site of action. Finally, we characterise in vitro four new bacterial glycosyl hydrolases and a lytic polysaccharide monooxygenase identified in our transcriptomic and proteomic analyses as some of the major bacterial enzymes involved in this unusual biological system.ConclusionBased on our data, we propose that bacteria and their enzymes are transported from the gills along the food groove to the shipworm’s mouth and digestive tract, where they aid in wood digestion.

Flake density and starch retrogradation influence in situ ruminal degradability characteristics of steam-flaked corn and predicted starch digestibility and energetic efficiency.

Five ruminally cannulated steers (body weight = 390 ± 7.86 kg) were used in two experiments to evaluate the effects of flake density and starch retrogradation on in situ ruminal degradation of steam-flaked corn. In experiment 1, sifted flakes with flake densities of 257, 296, 335, 373, and 412 g/L (enzymatic starch availabilities: 87%, 76%, 66%, 43%, and 49%, respectively) were evaluated in a randomized complete block design experiment. In experiment 2, the experimental design was a randomized complete block design with a 3 × 2 factorial arrangement of treatments. Three steam-flaked corn fractions corresponding to different particle sizes were used: flakes + fines (not sifted; >4 and <4 mm), sifted flakes (>4 mm), and sifted fines (<4 mm). Particle size fractions were stored for 3 d at either 23 °C or 55 °C (starch availabilities averaged across particle sizes: 53.3% and 25.5%, respectively) in heat-sealed foil bags. Samples were ruminally incubated for 0, 3, 6, 12, 24, 48, 72, or 96 h. Degradation data were modeled to obtain the rate and extent of degradation and passage rate was set to 6% per hour. In experiment 1, the rate of degradation decreased linearly (P < 0.01) and in situ ruminal dry matter (DM) degradability decreased linearly (P < 0.01) from 78.9% to 57.3% as flake density increased from 257 to 412 g/L. In experiment 2, storage of steam-flaked corn samples at 55 °C for 3 d decreased (P < 0.01) the rate of degradation by 37.6% across all particle sizes. Storing samples at 55 °C for 3 d decreased (P < 0.01) in situ ruminal DM degradability of flakes + fines, sifted flakes, and sifted fines by 20.9%, 22.6%, and 14.7%, respectively. Using data from experiment 1 and 2, enzymatic starch availability of sifted flakes was positively correlated (R2 = 0.97; P < 0.01) with in situ ruminal DM degradability. The results demonstrate that decreased starch availability resulting from either starch retrogradation or increased flake density is associated with decreased ruminal digestibility. Decreases in starch availability and in situ ruminal degradability may indicate that increasing flake density or starch retrogradation could potentially alter the site of digestion in cattle. Using prediction equations, decreases in ruminal starch digestibility of steam-flaked corn caused by increasing flake density or increasing starch retrogradation could increase energetic efficiency, depending on the rate of passage and if small intestinal starch digestibility is maintained.

356 Anomalies of Carbohydrate Digestion and Metabolism by Ruminants

Abstract Carbohydrate, derived either from plant cell walls (neutral detergent fiber; NDF) from fresh or conserved forages consumed by cows and growing cattle or from starch of grains and concentrates in commercial feedlot diets, provides most of the dietary energy for ruminant growth and production. The ruminants’ ability to harvest forage from remote, inaccessible locations, to scavenge energy from NDF of feeds and byproducts of grain largely indigestible by non-ruminants, and to employ non-protein N to form protein-rich, nutrient-dense foods for humans are key ecological advantages over non-ruminants. Outlined below are some topics needing research attention. First, feed composition tables invariably indicate that the digested energy (DE) of carbohydrates is 4.4 kilocalories per gram, yet the gross energy (GE) of purified carbohydrate polymers (starch; cellulose, glycogen) averages 4.18; monomers (hexoses, pentoses) average 3.74. Having DE exceed GE violates the first Law of Thermodynamics! Might this 5 percent discrepancy reflect underestimations of fecal lignin or of protein digestibility due to metabolic fecal N? Favoring feeds rich in carbohydrate, this discrepancy confounds formulation of least-cost diets. Secondly, site of digestion of carbohydrate alters its metabolizable energy (ME). Fermentation, though required to yield ME from NDF, generates methane and heat. In contrast, starches and sugars that escape ruminal fermentation, if digested in the small intestine, circumvent these losses increasing their relative ME. Unfortunately, when ruminally fermented, starch, either directly or via pH depression, reduces NDF fermentation; might ruminal NDF digestion be increased by feeding NDF plus buffer versus concentrate diet components asynchronously? Third, carbohydrate metabolites lost in urine (lactate, pentoses, hippuric acid) need further quantification. Finally, ruminally-formed metabolites (methylglyoxal, methane) adversely affect animal health and energetics. Ruminal modification (site- or time-targeted enzymes or inhibitors; altering the ruminal microbiome with pre- or probiotics, inoculants, nutraceuticals) should help enhance ruminant productivity and sustainability.