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Peptides are the important molecules in food protein that play a significant role in enhancing its flavor and taste. By controlling the generation of peptides, the flavor of food can be rebalanced to fit specific applications. Enzymatic hydrolysis of food proteins is a way to achieve the desired control on peptides, but it requires a careful selection of proteases and a controlled hydrolysis to maximize its potential.The main aim of this master thesis is to study S53 protease family for its applications in food sector. A previous study done in our lab suggested that this family consists of proteases with broad specificity (studied with synthetic substrates). Therefore, we hypothesized that they may not just degrade plant proteins but could also provide us with a diverse range of peptides (with varied sequences), where each peptide will have its own unique application in the food industry. To work on this hypothesis, firstly, we conducted gel electrophoresis experiments using the ten proteases (which could be expressed efficiently) of this family to investigate their proteolytic action towards four different proteins sources (chickpea, pea, sunflower, pumpkin). This initial study included various stages, starting from the identification of the dominant storage protein (in all the substrates) using SDS-PAGE followed by their digestion to produce hydrolysates. These hydrolysates were further studied by gel electrophoresis. Once, the proteases were tested for their activity, a bi-protease treatment was given to the protein sources with an aim to enhance the peptide generation.A total of 45 combinations were considered and an increase in peptide production in the resulting hydrolysates was studied using a florescence assay. A difference in relative fluorescent unit (RFU) values (obtained from the assay) was linearly related to the increase in peptide production from multi-protease treatment.SDS-PAGE results of protein sources showed various storage proteins in the range 15 to 75 kDa. All the S53 proteases were able to digest plant proteins, however with different proteolysis degree, signaling that different amount and composition of peptides were produced. Results from the florescence assay showed some protease combinations with RFU values greater than that of single-protease treatment. These findings helped us in screening some of the best protease blends for producing peptides which could be further studied to support new strategies for controlling the flavor of food proteins.

Objective: The study aimed to evaluate the effects of a mixture of encapsulated essential oils (EOs) addition on nutrient digestion, serum biochemical parameters, peripheral blood alpha-naphthyl acetate esterase (ANAE), and acid phosphatase (ACP-ase) positive lymphocyte ratios and intestinal morphology in laying hens.Methods: A total of 320 laying hens of 48-wk-old were randomly allotted into 4 treatment groups with 10 replicates of 8 birds in each replicate. The birds were fed a basal diet (control) or the diet added with mixture of EOs (which consist of eugenol, nerolidol, piperine, thymol, linalool, and geraniol) at 50, 100, and 200 mg/kg for period of 84 days.Results: The addition of EOs at 100 or 200 mg/kg increased the dry matter, organic matter, and crude protein digestion as compared to control. The addition of all doses of EOs did not affect serum gamma glutamyl transferase, alanine aminotransferase, and P but increased serum asparate aminotransferase (AST) concentration. The addition of 200 mg/kg EOs increased serum creatinine, while 100 mg/kg decreased Ca concentration. The addition of 100 and 200 mg/kg EOs generally improved ANAE and ACP-ase positive peripheral blood lymphocyte ratios and intestinal morphology.Conclusion: It can be concluded that, the addition of 100 or 200 mg/kg encapsulated EOs generally increased apparent nutrient digestion and serum AST concentration, improved ANAE and ACP-ase positive peripheral blood lymphocytes and intestinal morphology in laying hens.

En el primero de dos experimentos se determinó el efecto sobre el pH, la recuperación de materia seca (RMS) y la temperatura de ensilar triticale (x Triticosecale spp.) con o sin inoculante de bacteria homoláctica (IBH), utilizando 30 minisilos de vidrio de 0.946 L sellados al vacío (GJ) por tratamiento, que se abrieron a los días 0, 1, 2, 3, 5, 7, 14, 30, 105 y 123 de fermentación. Abarcando todos los largos de fermentación, la inoculación redujo (P0.05) en la RMS relativo al ensilaje sin IBH. Ambos ensilajes tuvieron un pH similar (P>0.05) al finalizar el periodo de fermentación de 123 d. En el segundo experimento se compararon las características nutricionales, la fermentación y la estabilidad aeróbica del triticale ensilado con o sin IBH durante 123d en minisilos de 3L hechos de PVC y empacados manualmente o de GJ y sellados al vacío. Hubo mínimas diferencias (P>0.05) en el contenido nutricional del ensilaje fermentado en minisilos de PVC o GJ y la inoculación tampoco afectó estas variables. El ensilamiento de triticale disminuyó (P0.05) con los ensilados en GJ. No hubo diferencia entre los ensilajes (P>0.05) en FDN no degradable a las 240 h (uFDN240), digestibilidad de FDN en el tracto entero (TTNDFD) y la velocidad de digestión de la FDN (NDFkd). El triticale fermentó bien en los minisilos de vidrio, sin embargo, la cantidad de material ensilado puede que no haya sido suficiente para poder detectar diferencias debido a la inoculación.

The gastric digestion behavior of differently processed goat milks was investigated using a dynamic in vitro gastric digestion model, the human gastric simulator. Homogenization and heat treatment of goat milk resulted in gastric clots with highly fragmented structures. They also delayed the pH reduction during digestion, altered the chemical composition of the clots and the emptied digesta, promoted the release of calcium from the clots, and accelerated the hydrolysis and the emptying of milk proteins. The apparent density of the protein particles and the location of the homogenized fat globules changed during the digestion process, as shown in the emptied digesta of the homogenized goat milks. The effects of processing on the digestion behavior of goat milk were broadly similar to those previously reported for cow milk. However, the overall gastric digestion process of goat milk was more affected by homogenization than by heat treatments.

Background Bovine milk κ-casein-derived caseinomacropeptide (CMP) is produced in large quantities during cheesemaking and has various biological activities demonstrated via in vitro and in vivo experiments. Previous studies examined protein degradation and peptide release after casein or whey protein consumption. However, whether purified intact CMP which is partially glycosylated survives intact to its presumed site of bioactivity within the gut remains unknown. Objective The aim of this study was to determine the extent to which purified intact CMP (including glycosylated forms) is digested into peptide fragments within the jejunum of healthy human adults after consumption. Methods Jejunal fluids were collected from three adult participants (two men and one woman, age: 27 ± 7, BMI: 23 ± 1) for three hours after consuming 37.5 g of purified intact CMP. CMP and CMP-derived peptides were isolated from the collected jejunal fluids by ethanol precipitation and solid phase extraction and identified by mass spectrometry-based top-down glycopeptidomics. Relative abundances of CMP and CMP-derived peptides were compared qualitatively between the feed and the jejunal fluids. Results Intact CMP was dominant in feeding material, accounting for 90% of the total ion abundance of detected peptides, and in very low abundance (less than 2%) in the jejunal fluids. CMP-derived fragment peptides ranging from 11-20 amino acids in length were predominant (accounting for 68-88% of the total peptide ion abundance) in jejunal fluids during 1-3 h post consumption. Conclusions This study demonstrates that intact CMP (including glycosylated forms) is mostly digested in the human jejunum, releasing a wide array of CMP-derived peptide fragments. Some of the CMP-derived peptides with high homology to known bioactive peptides consistently survived across 3 h of digestion. Therefore, future research should examine the biological effects of the partially digested form-the CMP-derived fragments-rather than that of intact CMP.

Background:Worldwide, the prevalence of obesity and related non-communicable chronic diseases is high and continues to grow. In that sense, anthocyanins (ANC) have shown beneficial health effects in preventing obesity and metabolic risk factors. Moreover, the demand for functional foods incorporating these compounds has risen significantly in the past years. Thus, there is a need for validations of the functional properties of these formulations; nevertheless, in vivo assays are complex and require a lot of resources. One approach for estimating bioactive compounds' functionality and health benefits is to evaluate their bioaccessibility on a specific food matrix, determined by various factors. This article aims to review different factors influencing the bioaccessibility of ANC evaluated on in vitro digestion models as a functionality parameter, elucidating the effect of chemical composition, raw materials, food matrices, and vehicles for the delivery of ANC.Methods:Study searches were performed using PubMed, Web of Science, Scopus, and Science Direct databases.Results:Different factors influenced bioaccessibility and stability of ANC studied by in vitro digestion: i) the raw material used for ANC obtention; ii) food processing; iii) other food components; iv) the extraction method and solvents used; v) the structure of ANC; vi) delivery system (e.g., microencapsulation); vii) pH of the medium; viii) the digestion stage.Conclusion:Simulated digestion systems allow to determine free or encapsulated ANC bioaccessibility in different food matrices, which offers advantages in determining the potential functionality of a food product.

The in-vitro gastrointestinal digestion behaviour of an oil-in-water emulsion with an interface consisting of nano-sized droplets coated with caseinate particles, referred to as a droplet-stabilised emulsion (DSE), was explored using the human gastric simulator and pH-stat models. A caseinate-particle-stabilised emulsion (PSE) was used as a control, with a similar droplet size distribution and the same composition as the DSE. The nanodroplet-stabilised interface of the DSE was preserved during the first 180 min of gastric digestion. During 240 min, the droplet sizes of the DSE and the PSE increased from 22.71 ± 1.14 to 63.34 ± 6.57 μm and from 17.98 ± 1.16 to 85.11 ± 9.35 μm respectively. The small droplet size of the DSE that was released from the gastric phase contributed to slightly higher total free fatty acid (FFA) release (56.18 ± 3.55%) than that from the PSE (49.4 ± 2.67%). The FFA release rate of the DSE (1.21 % min−1) was greater than that of the PSE (1.06 % min−1) during the first 30 min of small intestinal digestion; similar FFA release rates (0.5 µmol s−1 m−2 × 10−4) were obtained for both emulsions beyond 30 min of digestion. This study provides new information on lipid digestion using a novel interfacial layer that was stabilised with nanodroplets.

Background It is necessary to propose plant alternatives to animal proteins that are of good nutritional quality. Pea is a good candidate owing to its high protein content and its well-balanced amino acid (AA) profile. Objective This study aimed at assessing the real ileal AA and nitrogen digestibility (RIDAA and RIDN) of pea protein isolate as compared to milk casein in humans. It also aimed to evaluate their nutritional quality through calculation of the digestible indispensable amino acid score (DIAAS) and to determine the net postprandial protein utilization (NPPU). Methods Fifteen healthy volunteers were included in a randomized, single-blinded, 2-arms parallel design, trial. They were equipped with a naso-ileal tube. They ingested the test meals, which consisted of nine successive portions of mashed potatoes containing either pea protein or casein, intrinsically labelled with 15N. Ileal content, plasma and urine samples were collected regularly over an 8 h postprandial period. Results Mean RIDAA was 93.6 ± 2.9% for pea protein and 96.8 ± 1.0% for casein, with no difference between the sources (P = 0.22). Leucine, valine, lysine and phenylalanine were significantly less digestible in pea than in casein. The RIDN was 92.0 ± 2.7% and 94.0 ± 1.7% for pea protein and casein, respectively, and was not different (P = 0.11). The DIAAS was 1.00 for pea protein and 1.45 for casein. The NPPU was 71.6 ± 6.2% and 71.2 ± 4.9% for pea protein and casein, respectively (P = 0.88). Conclusion Although some AAs are less digestible in pea protein than in casein, the RID and the NPPU were not different. The DIAAS of 1.00 obtained for pea protein demonstrated its ability to meet all AA requirements. This study shows the potential of pea isolate as a high quality protein. This study was registered at clinicaltrials.gov as NCT04072770.

This study aimed to explore the optimum conditions for the ultrasonic-enzyme-assisted extraction of comfrey (Symphytum officinale L.) polysaccharides (SOP) by the response surface methodology (RSM). The optimum extraction conditions included an extraction time of 62 min, an enzyme complex dose of 1.1 %, a liquid-to-solid ratio of 21 mL/g, and a pH value of 6. A SOP yield of 20.32 % was achieved. The digestion and fermentation behaviors of SOP in vitro were determined. A digestion test was performed in simulated gastric fluid (SGF) and simulated intestinal fluid (SIF). A fermentation model was prepared with the cecal contents of chickens. The results showed that SGF (2.15 ± 0.09 %) and SIF (1.08 ± 0.06 %) were ineffective in the digestion of SOP. During fermentation, the pH values of the culture medium were lower than the initial pH (7.75 ± 0.03). SOP (47.06 ± 1.79 %) was used by the chicken cecal microbiota, which produced 34.12 ± 0.79 mg/mL short-chain fatty acids at 48 h. Moreover, the composition of the chicken cecal microbiota could be regulated by SOP during fermentation. The relative abundance of Lactobacillus at the genus level was improved. Therefore, SOP might have the potential to serve as a prebiotic in chicken production.

β-Lactoglobulin (β-LG) is a major milk protein, making up more than 53% of the total whey proteins, and is seen as a valuable ingredient in food processing because of its high essential amino acid content and diverse functional applications. The Maillard reaction can occur during the storage and processing of food and generate various beneficial effects, including anti-allergenicity, antioxidant, and immunomodulatory effects. The addition of an β-LG-lactose conjugate (LGL) produced by the Maillard reaction was shown to have a strong immune-enhancing effect, increasing both nitric oxide generation and cytokine expression through activation of RAW 264.7 cells, even after in vitro digestion. Furthermore, daily LGL administration resulted in the upregulation of several immune markers in a cyclophosphamide-induced immunosuppressive mouse model, indicating that this treatment stimulates multiple immune cells, including macrophages, natural killer cells, and lymphocytes, enhancing the proliferation and activation of both the innate and adaptive immune responses. Taken together, these findings indicate that consuming LGL on a regular basis can improve immunity by increasing the natural production of various immune cells.

A study was conducted to investigate the inclusion effects of sugar beet pulp and rice straw mixture silage with inoculation (BRMS), in place of whole-plant corn silage (CS), on the dry matter intake, total-tract nutrient digestibility, plasma metabolites, rumen fermentation, and lactation performance in high-production dairy cows. Sixteen multiparous Holstein cows (body weight, 622 ± 35 kg; days in milk, 90 ± 11 d; mean ± standard deviation) were used in our experiments; the experiments were based on a repeated 4 × 4 Latin square design for 21 d, and each experimental period consisted of 14 d of adaptation, followed by 7 d of data collection. The 4 dietary treatments used were (dry matter basis): (1) 0% BRMS and 28.6% CS (0BRMS); (2) 4.3% BRMS and 24.3% CS (15BRMS); (3) 8.60% BRMS and 20.0% CS (30BRMS); and (4) 12.9% BRMS and 15.7% CS (45BRMS). The increasing inclusion of dietary BRMS was observed to linearly increase the total volatile fatty acids and the propionate concentration. The dry matter intake and digestibility values of neutral detergent fiber and acid detergent fiber increased linearly as the percentage of BRMS increased up to 45%. Milk yield linearly increased with the increase in the content of BRMS (39.0, 39.8, 40.9, and 40.3 kg/d for 0BRMS, 15BRMS, 30BRMS, and 45BRMS, respectively). The increasing inclusion of dietary BRMS induced a decrease in the ammonia nitrogen and milk urea nitrogen concentration, leading to a linear increase in milk protein production (1.15, 1.26, 1.35, and 1.27 kg/d for 0BRMS, 15BRMS, 30BRMS, and 45BRMS, respectively). In conclusion, the diets with the replacement of CS with BRMS up to 45% were beneficial to the production performance of high-production dairy cows, indicating that this method may be an appropriate use of sugar beet pulp and rice straw.

Introduction: Nephrilin-class peptides, designed inhibitors of Rictor complex, have previously demonstrated efficacy against a wide range of systemic responses to stress, alleviating clinically relevant variables in a rat scald model and sepsis mortality in a mouse model. This study explores the possibility that Nmod3N1vA and Nmod3N1vAS3 peptides, extended versions of a previously reported N-modulin, Nmod3sN1v (“V-nephrilin”) can attenuate respiratory distress and associated immunological markers in a male rat scald-endotoxemia model. Methods: Nmod3sN1v peptide was C-terminally extended with a d(AVD) tripeptide to extend the iron-binding pocket. The peptide Nmod3N1vAS3 additionally contains a YLK motif, which has been shown to inhibit STAT3 activation [15]. Rats were treated with each N-modulin peptide (1 mg/kg) by subcutaneous bolus injection on days 1–7 post-burn, then received a single bolus injection of LPS (0.5 mg/ml). Oximeter readings were captured for 4 h thereafter and branchoalveolar lavage (BAL) fluid, lung tissue, plasma and splenocytes were collected at sacrifice. Flow cytometry was performed on splenocytes and BAL cells. Results: d(AVD)-extended Nmod3N1vA showed increased resistance to exoprotease digestion in vitro. Compared to untreated scald control animals and those treated with Nmod3sN1v, Nmod3N1vA and Nmod3N1vAS3 showed differences in biodistribution to lung tissue (

Egg white has high protein content and numerous biological/functional properties. However, the reported allergenicity for some of the proteins in the egg white is an issue that needs to be paid exclusive attention. A consideration on the structure of the IgE epitopes and their sequences as well as a comprehensive understanding of the effects of various processes on the epitopes and the impact of the gastrointestinal tract on them can help target such issues. The current study focuses on the identified IgE epitopes in the egg white proteins and evaluates the effects of gastrointestinal digestion, carbohydrate moiety, food matrix, microbial fermentation, recombinant allergen, heat treatment, Maillard reaction and combination of the various processes and gastrointestinal digestion on the egg white allergenicity. Although the gastrointestinal tract reduces the immunoreactivity of native egg white proteins, some of the IgE epitope-containing fragments remain intact during the digestion process. It has been found that the gastrointestinal tract can have both positive and negative impacts on the IgE binding activities of egg white proteins. Elimination of the carbohydrate moiety leads to a reduction in the immunoreactivity of ovalbumin. But, such effects from the carbohydrate parts in the IgE binding activity needs to be explored further. In addition, the interaction between the egg white proteins and the food matrix leads to various effects from gastrointestinal tract on the digestion of egg white proteins and their subsequent immunoreactivity. Further on this matter, studies have shown that both microbial fermentation and Maillard reaction can reduce the IgE binding activities of egg white proteins. Also, as an alternate approach, thermal process can be used to treat the egg white proteins which may result in the reduction or increase in their IgE binding activities depending on the conditions used in the process. Overall, based on the reported data, the allergenicity levels of egg white proteins can be mitigated or escalated depending on the conditions applied in the processing of the food products containing the egg white. So far, no practical solutions have been reported to eliminate such allergenicity.

Exploring new alternative sources of feedstuffs can contribute to animal production sustainability in some Mediterranean regions in order to overcome the rising food demand. The influence of dietary replacement of wheat straw (WS) with orange waste silage (OWS) on nutrient intakes, apparent digestibility, ruminal fermentation and blood biochemical constituents and milk production of dairy goats were evaluated. Forty pregnant goats (46.30±1.6 kg BW) were housed in individual pens in a completely randomized design and fed (ad libitum) a TMR for 75 days period. Goats were assigned to four experimental diets with the forage amounts consisting of either WS as a control diet (1000 g WS/kg DM in the TMR), a 50:50 mixture of both WS and OWS (500 g WS and 500 g OWS/kg DM in the TMR), an orange waste silage (1000 g OWS/kg DM in the TMR) or corn silage as a positive control (1000 g CS/kg DM in the TMR). The DMI increased linearly (P3-N concentration and total protozoa abundance decreased quadratically (P

Background: Dicarbonyls are highly reactive compounds and major precursors of advanced glycation end products (AGEs). Both dicarbonyls and AGEs are associated with development of age-related diseases. Dicarbonyls are formed endogenously but also during food processing. To what extent dicarbonyls from the diet contribute to circulating dicarbonyls and AGEs in tissues is unknown.Objectives: To examine cross-sectional associations of dietary dicarbonyl intake with plasma dicarbonyl concentrations and skin AGEs.Methods: In 2566 individuals of the population-based Maastricht Study (age: 60 +/- 8 y, 50% males, 26% with type 2 diabetes), we estimated habitual intake of the dicarbonyls methylglyoxal (MGO), glyoxal (GO), and 3-deoxyglucosone (3-DG) by combining FFQs with our dietary dicarbonyl database of MGO, GO, and 3-DG concentrations in> 200 commonly consumed food products. Fasting plasma concentrations of MGO, GO, and 3-DG were measured by ultra-performance liquid chromatography-tandem mass spectrometry. Skin AGEs were measured as skin autofluorescence (SAF), using theAGE Reader. Associations of dietary dicarbonyl intake with their respective plasma concentrations and SAF (all standardized) were examined using linear regression models, adjusted for age, sex, potential confounders related to cardiometabolic risk factors, and lifestyle.Results: Median intake of MGO, GO, and 3-DG was 3.6, 3.5, and 17 mg/d, respectively. Coffee was the main dietary source of MGO, whereas this was bread for GO and 3-DG. In the fully adjusted models, dietary MGO was associated with plasma MGO (beta: 0.08; 95% CI: 0.02, 0.13) and SAF (beta: 0.12; 95% CI: 0.07, 0.17). Dietary GO was associated with plasma GO (beta: 0.10; 95% CI: 0.04, 0.16) but not with SAF. 3-DG was not significantly associated with either plasma 3-DG or SAF.Conclusions: Higher habitual intake of dietary MGO and GO, but not 3-DG, was associated with higher corresponding plasma concentrations. Higher intake of MGO was also associated with higher SAF. These results suggest dietary absorption of MGO and GO. Biological implications of dietary absorption of MGO and GO need to be determined. The study has been approved by the institutional medical ethical committee (NL31329.068.10) and the Minister of Health, Welfare and Sports of the Netherlands (Permit 131088-105234-PG).

In this work, holocellulose nanocrystals (hCNCs) was isolated from burdock insoluble dietary fiber (IDF) by enzymatic hydrolysis and ultrasonic treatment and their inhibitory effects against α-Amylase and α-Glucosidase were investigated. The hydrodynamic diameter of hCNCs decreased from about 600 to 200 nm with increasing sonication time, accompanied by an improvement in cellulose and glucose content. Steady-state fluorescence studies suggested that static complexes were formed between hCNCs and α-Amylase or α-Glucosidase via a spontaneous and endothermic approach, which was driven by both hydrophobic interactions and hydrogen bonding. The median inhibitory concentration (IC50) values of hCNCs against the tested enzymes were positively correlated with their size, and noncompetitive type and mixed type of inhibition was detected using Lineweaver-Burk plots. During the simulated digestion, the inclusion of burdock hCNCs obviously retarded the starch hydrolysis in both dose- and size-dependent manner, suggesting their potential in blocking postprandial serum glucose upsurge.

Microplastics (MPs), polymer particles capable of accumulating heavy metals from ambient medias, have been widely found in agriculture and pasture soils. Through the consumption of MPs in soils, heavy metals adsorbed on MPs can be transported into ruminant digestive guts. To explore the behavior of Cd loaded MPs in ruminant digestive system, we initially established a ruminant digestive in-vitro method (RDM) that simulates the rumination cycle between mouth and rumen to evaluate the release rates of Cd on 4 most commonly used undegradable MPs (PE, PP, PVC, and PS) and a biodegradable MP (PLA). After 120 h of adsorption, the Cd adsorption capabilities by 5 MPs ranged from 0.23 μg/g to 2.45 μg/g. Through RDM, all tested Cd loaded MPs released high proportions of Cd with release rates from 21.5% to 41.8%, where PLA showed the highest Cd release rate. Cadmium was mainly released in rumen and abomasum phases, and the rumination cycle between mouth and rumen can affect the Cd release from MPs. The present study provides a new view on the environmental hazard of heavy metal and MP pollution that their co-exposure to ruminants should be taken into account.

Medium-chain triglyceride (MCT) and eicosapentaenoic acid (EPA) has been widely applied in nutritional supplementation. However, when administered individually or mixed, they were unable to maximize their nutritional value. Hence, EPA-rich medium- and long-chain triacylglycerol (MLCT) was synthesized from MCT and EPA-rich fish oil (FO) by enzymatic transesterification. The fatty acids in triglyceride (TAG) were rearranged and resulted in significant changes in TAG profiles compared to physical mixture of MCT and FO (PM). EPA-containing MML (MML, MLM and LMM) and LLM (LLM, LML and MLL) type TAGs account for 70.21%. The fate of different oils (MCT, FO, PM, and MLCT) across the gastro-intestinal tract was subsequently simulated by an in vitro digestion model. The results showed that the physical and structural characteristics of different oils during digestion depended upon the oil type and the microenvironment they were in. The degree of hydrolysis for MLCT was higher than that for the other three oils. FFAs release level was presented in the following order: MLCT＞MCT＞PM＞FO. This can be attributed to the composition and positional distribution of fatty acids in TAGs. What is more, LCFAs (EPA) in MLCT mainly existed in the form of sn-2 MAG, which was conducive to their subsequent absorption and transport.These results may aid in the future rational design of structural lipids, thereby regulating lipid digestion and maximizing the nutritional value of oils.

The physiological function of the reticulorumen plays an essential role in ruminant nutrition, and detailed knowledge of rumen motility can further advance understanding of ruminant nutrition and physiology. Rumen motility was simulated by setting different stirrer rotation speeds in a rumen simulation technique (RUSITEC) system. The aim of this study was to investigate the effects of rotation speeds on rumen fermentation, saturation factor of dissolved gases, hydrogen (H2) and methane (CH4) emissions, microbial protein synthesis, and selected microbial population using RUSITEC. The experiment was performed according to a balanced 3 × 3 Latin square design, and each period included 7 d for adaptation and 3 d for sampling. Three motility treatments included 5, 15, and 25 rpm rotation speeds. Daily total gas and H2 and CH4 emissions had quadratic responses to the increasing rotation speed and were highest at 15 rpm. Quadratic and linear responses (highest at 5 rpm) to increasing rotation speed were observed for saturation factors of H2 and CH4, liquid-dissolved H2 and CH4 concentrations, and headspace concentration of H2 in the gas phase, whereas increasing rotation speed linearly decreased saturation factors of CO2 and liquid-dissolved CO2 concentration. Quadratic and linear responses to increasing rotation speed were observed for molar percentages of acetate, ammonia, and microbial protein concentration, whereas increasing rotation speed quadratically increased pH and decreased total volatile fatty acid concentration and acetate-to-propionate ratio. The 15-rpm rotation speed had the highest values of total volatile fatty acids, acetate molar percentage, and microbial protein concentration. Quadratic and linear responses to increasing rotation speed were observed for copy numbers of solid-associated fungi and fluid-associated bacteria, fungi, and protozoa, while increasing rotation speed linearly increased copy numbers of solid-associated protozoa. Rotation at 15 rpm increased populations of fungi and protozoa in the solid rumen contents and the population of bacteria and fungi in the liquid rumen contents. In summary, this study provides insights on the biofunction of proper rumen motility (i.e., at a rotation speed of 15 rpm), such as improving feed fermentation, increasing gas emissions with decreased dissolved gas concentrations and saturation factors, and promoting microbial colonization and microbial protein synthesis, although further increase in rotation speed (i.e., to 25 rpm) decreases feed fermentation and microbial protein synthesis.

1. The objective of this study was to examine the influence of dietary soluble non-starch polysaccharide (sNSP) level and xylanase supplementation on productive performance, viscosity and pH along the gastrointestinal tract in laying hens. Excreta moisture content, ileal and caecal microbiota and short-chain fatty acid (SCFA) composition and apparent total tract nutrient utilisation were measured.2. Hyline Brown laying hens (n = 144) were housed individually at 25 weeks of age and allocated to one of the four wheat-based dietary treatments in a 2 × 2 factorial arrangement, consisting of two levels of sNSP (High 13.40 g/kg or Low 11.22 g/kg), with or without xylanase (0 or 12,000 BXU/kg). Birds were fed the dietary treatments for 56 d.3. Increasing dietary sNSP increased jejunum viscosity, degradability of total NSP, total tract flow of insoluble arabinose, and succinic acid concentration in the caeca (P 0.05). Feeding high sNSP decreased excreta moisture content, total tract energy retention and free oligosaccharide, total tract flow of soluble and insoluble galactose and insoluble rhamnose and fucose, and ileal acetic and lactic acid concentrations (P 0.05), and tended to reduce egg production (P = 0.058).4. Supplementation with xylanase resulted in reduced jejunum and ileum viscosity, caecal pH, excreta moisture, flow of soluble arabinose and glucose and insoluble arabinose and xylose, caecal concentration of

Gut health or intestinal health is frequently discussed without any clear definition as to its meaning. It is suggested that this should be defined as intestinal integrity and functionality as both are a pre-requisite for the health of the intestine itself and the host. The health of the intestine is dependent upon a successful evolution of the absorptive capacity of the intestine, which in turn is influenced by the co-evolution of the intestinal immune systems and the microbiota. Nutrient supply plays a significant role in this process and from the perspective of the microbiota this changes with age as the intestines and upper gastrointestinal tract (GIT) microbiota become more effective in nutrient removal. Feed enzymes play a significant role in this process. Phytases can improve digestion of minerals, amino acids and energy and as a result reduce the availability of nutrients in the lower intestines for the microbiota. Protease can have a similar effect with amino acid supply. Non-starch polysaccharidases (NSPases) have a unique role in that they not only improve diet digestibility from the hosts perspective, thus limiting nutrient supply to the microbiota, but they also release soluble fragments of fibre from the insoluble matrix and/or depolymerize high molecular weight viscous fibre fractions in to smaller, more fermentable carbohydrate fractions. This results in a more favourable balance between fermentable carbohydrate to protein supply, a ratio which is deemed critical to maintaining good intestinal health. The dynamic nature of this complex evolution needs greater consideration if antibiotic free production is to succeed. © 2021 The Authors. Journal of The Science of Food and Agriculture published by John WileySons Ltd on behalf of Society of Chemical Industry.