Intestinal Digestion Research Articles

In vitro gastrointestinal digestibility and lipid oxidation of fish oil-in-water emulsions: Influence of different EPA/DHA ratios

The long-chain omega-3 polyunsaturated fatty acids (ω-3 PUFAs) eicosatetraenoic acid (EPA) and docosahexaenoic acid (DHA) are known to play roles in supporting human health, primarily by reducing inflammation and promoting its resolution. In this study, the impacts of EPA/DHA ratios (5.13/1, 2.45/1,1.34/1) on lipid oxidation and digestion behaviors were explored using an in vitro digestion model. Emulsions were characterzied by droplet size, zeta-potential as well as microstructure. Additionally, the release of free fatty acids (FFAs), lipid hydroperoxides (LPO) and thiobarbituric acid reactive substance (TBARS) were also investigaed throughout simulated digestion phases. Notably, for all EPA/DHA ratios, from saliva fluid to gastric fluid, droplet size was slightly changed, accompanied by a significant decrease in absolute zeta-potential, followed by an increase in both parameters after intestinal digestion. Emulsions with the lowest ratio of EPA/DHA (i.e., 1.34/1) exhibited lower FFA release compared to those with higher ratios (i.e., 5.13/1 and 2.45/1). Conversely, the lowest EPA/DHA ratio increased oxidation during the intestinal phase, as indicated by elevated LPO and TBARS levels. This study clearly suggests that EPA/DHA ratios influence the oxidative stability of fish oil emulisions during digestion and provides useful information to formulate fish oil supplementation that improves in vivo oxidative status.

Study on Rumen Degradability and Intestinal Digestibility of Mutton Sheep Diets with Different Concentrate-to-Forage Ratios and Nonfiber Carbohydrates/Neutral Detergent Fiber Ratios.

This study was conducted to investigate the rumen degradability and intestinal digestibility of mutton sheep diets different in concentrate-to-forage ratio, NFC/NDF, and ingredient combination, providing a guideline for the selection of a fattening diet for mutton sheep. Twenty-eight diets composed of four raw material combinations and seven concentrate-to-forage ratios and four three-year-old mutton sheep with permanent rumen fistulas were used in the experiments. The nutrient composition of the diets was first analyzed, and then an in situ method and in vitro three-step method were separately used to measure the rumen degradability and intestinal digestibility, mainly focusing on the effects of dietary concentrate-to-forage ratio and NFC/NDF as well as the effects of soybean meal and soybean meal replacement and peanut vine and peanut vine replacement. The results showed that a dietary concentrate-to-forage ratio of 70:30~80:20 and an NFC/NDF ratio of 1.5~2.0 are recommended for fattening mutton sheep, and low-cost cottonseed meal and rapeseed meal can be feasible alternative protein sources to soybean meal. In addition, the nutritional values of sunflower seed hulls and rice hulls for mutton sheep are lower than that of peanut vine. Such a study can provide practical guidelines for enterprises and farmers, being of important significance for the high-quality development of the mutton sheep industry.

UV-crosslinked collagen-chondroitin sulfate nanofibers: Insights on production, characterization, in-vitro digestibility

Electrospun polymer nanofibers have significant attention in various fields. In this study, collagen/chondroitin sulfate (Col/CS) nanofibers were fabricated by electrospinning, the effect of solution and processing parameters on fiber morphology was investigated. The resulting fibers were exposed to UV light for the crosslinking process. Granola bars with Col/CS nanofibers were prepared and subjected to in vitro digestion. The electrospun Col/CS nanofibers, fabricated at a 95:5 (w/w) ratio under 26 kV voltage, 0.8 mL/h feeding rate, and a 15 cm tip-to-collector distance, exhibited a smooth, bead-free fibrous morphology with an average diameter of 79.88 ± 6.01 nm. After UV-crosslinking, no new bands were observed in the FTIR spectrum, but notable changes occurred in the Amide I and II regions. Granola bars containing Col/CS nanofibers exhibited significantly higher Col content in the intestinal digestion fraction of in vitro digestion compared to the control group (free Col + CS). On the other hand, no significant difference was observed between the CS content of the samples after intestinal digestion. These findings demonstrate that electrospinning followed by UV crosslinking is an effective method for producing Col/CS fibers without the use of harsh solvents, highlighting Col/CS nanofibers as promising candidates for the development of novel functional foods.

Study on stability of rose anthocyanin extracts and physicochemical properties of complex with whey protein isolate after spray drying.

Pingyin rose is an edible flower rich in anthocyanins. In this study, antioxidant capacity and color were used as the main evaluation indexes to investigate the effects of common physical and chemical factors on the stability of rose anthocyanin extracts (RAEs). In addition, the physicochemical properties of the whey protein isolate (WPI)-RAEs complex after spray drying were studied. Vitamin C, temperature, and some metal ions can cause different degrees of discoloration of RAEs solution. More importantly, heat treatment, as well as most metal ions and sugars, had no significant effect on the antioxidant capacity of RAEs solution (p>0.05). Moreover, compared to spray-dried pure WPI, the WPI-RAEs powder was delicate and uniform, and had higher particle size, bulk density, moisture activity, and better gel properties. The release rate of all WPI-RAEs sol/gel to RAEs reached about 89% in the intestinal digestion stage, but the WPI-RAEs interaction reduced the digestibility of protein in the intestinal digestion stage. We hope that this study can provide a theoretical basis for the development and utilization of WPI-RAEs as food ingredients.

Correlation of in vitro digestibility with chemical composition and bioaccessibility of phenolic compounds in date pomace and antioxidant potential

ABSTRACT This study aimed to evaluate the chemical composition and impact of in vitro gastrointestinal digestion on the recovery, bioaccessibility, indices, and changes in the bioactive compounds of date pomace. Bioactive compounds were extracted using various solvents. The results revealed that pomace is a rich source of fiber. Methanol was found to be the most effective solvent for extraction of the bioactive compounds. A high recovery index for phenolic and flavonoid compounds and high antioxidant activity were obtained for the sample subjected to mouth-digestion. The bioaccessibility index revealed that a low percentage of phenols and flavonoids was available for absorption in the intestine. The TPC, TFC, and antioxidant activities (DPPH and ABTS) were positively correlated (r = 0.855-0.995) with oral, gastric, and intestinal digestion. Date pomace is an excellent source of bioactive compounds that can be utilized in the formulation of functional foods with health benefits.

Essential oil release from zein particles as modulated by inorganic coating and biopolymeric networking

Zein particles (ZPs) have emerged as a popular delivery carrier for hydrophobic bioactive substances. However, some lipophilic compounds are easily released from ZPs because of the low polarity compatibility between zein and the compounds. The loss of encapsulated substances is particularly evident for citrus essential oil (CEO), an extremely hydrophobic ingredient. The premature release of CEO from ZPs was mitigated by developing a modification approach using ZPs coated with calcium phosphate (CaP) and networked with Ca2+-alginate gel (CaAlg). The approach involved the preparation of ZPs (through the antisolvent addition procedure) in phosphate buffer, and supplementation of the particles consecutively with sodium alginate and Ca2+ ions (as CaCl2). This procedure resulted in retention of up to 28% of CEO within ZPs after the accelerated storage experiment. Under in vitro gastric and intestinal digestion condition, the CaP-coated and CaAlg-networked ZPs had a significantly lower release of CEO compared to their non-coated and non-networked counterparts. The morphology of the particles was investigated by scanning (SEM) and transmission (TEM) electron microscopies, as well as confocal laser scanning microscopy. SEM imaging showed that sodium alginate could facilitate the formation of CaP coating through preventing CaP crystallization. CaP coating also decreased the ZPs fusion/aggregation as evidenced by comparing the ζ-potential and microscopic morphology of the particles. Examination of the infrared spectra of the particles revealed that the formation of CaP coating occurred at Ca2+ ion concentrations ≥ 10 mM.

Gastrointestinal-inert prebiotic micro-composites improve the growth and community diversity of mucosal-associated bacteria.

The process of microencapsulation and the development of microparticle-based drug formulations have gained increased pharmaceutical interest, particularly for drug delivery and bacterial-encapsulation purposes for probiotic delivery. Existing studies have examined microcomposite (MC) responses to gastrointestinal (GI) conditions with the aim of controlling disintegration, and thus release, across the small and large bowel. However, the delivery of MCs which remain intact, without degrading, could act as bacterial growth scaffolds or materials providing a prebiotic support, conferring potentially beneficial GI health properties. This present study employs prilling as a method to produce a portfolio of MCs using a variety of biopolymers (alginate, chitosan, pectin and gellan gum) with a range of MC diameters and density compositions. Fluorescent probes are co-encapsulated within each MC to enable flow-cytometry directed release profile assessments following exposure to chemical simulated gastric and intestinal digestion conditions. We observe that MC size, gel-strength, density, and biopolymer material all influence response to gastric and intestinal conditions. Gellan gum (GG) MCs demonstrated complete resistance to disintegration throughout GI-simulation in the stomach and small intestine. Considering these MCs could reach the colon intact, we then examined how such MCs, doped with prebiotic growth supporting carboxymethyl cellulose (CMC) polymers, could impact microbial communities using a bioreactor model of the colonic microbiome. Following supplementation with GGCMC MCs, mucosal bacterial diversity (using 16 s rRNA sequencing and Shannon entropy and observed feature diversity metrics) and taxonomic composition changes were observed. Concentrations of short chain fatty acid (SCFA) metabolites were also found to be altered. This is the first study to comprehensivelyexamine how MC physicochemistry can be manipulated to tailor MCs to have the desired GI release performance and subsequently, how GI-resistant MCs could have influential microbial altering properties and be adopted in novel prebiotic strategies.

Ruminal degradation and intestinal digestion of developed oat (Avena sativa L.) varieties in comparison with barley grain in dairy cows

This study aimed to evaluate the ruminal degradation and intestinal digestion of nutrients of two cultivars of oat grains (CDC Nasser and CDC Seabiscuit) in comparison with a barley grain (CDC Meredith that was considered the control treatment) in dairy cows. Nasser showed higher rumen undegradable protein (RUP; P < 0.01) and intestinal digestible protein ( P < 0.01) than Seabiscuit or control. However, the total digestible protein was not different among grain varieties ( P = 0.25). The in vitro intestinal digestibility of RUP (dIBP) for Nasser was higher than control ( P = 0.02); however, the dIBP in Seabiscuit did not differ from other cultivars. The intestinal digestible rumen bypass starch and total digestible starch were lower in the oat grain varieties than in the control ( P < 0.01). The truly absorbed protein supplied to the small intestine (DVE) was highest for control, intermediate for Seabiscuit, and lowest for Nasser ( P < 0.01). Moreover, control showed a higher estimated feed milk value than oat varieties ( P < 0.01). In conclusion, Seabiscuit shared similar rumen degradation and intestinal digestibility with control suggesting that Seabiscuit oat grain could in some extension replace barley grain in diets for dairy cows.

In vitro digestion study comparing a predigested glycerolysis product versus long-chain polyunsaturated fatty acid-rich oils (LCPUFA) as a strategy for administering LCPUFA to preterm neonates

Background & aimsMaintaining an adequate supply of arachidonic acid (ARA) and docosahexaenoic acid (DHA) is essential for optimal growth of preterm infants. This study aims to evaluate and compare the digestibility and bioaccessibility of ARA and DHA oils compared to their predigested product through an in vitro digestion model. MethodsAn in vitro gastrointestinal digestion model was used in two stages: gastric digestion and intestinal digestion. Samples of two polyunsaturated rich oils (ARA and DHA oils) and their predigested product (2:1, ARA: DHA) produced by enzymatic glycerolysis have been digested for 120 min. The final digestion product obtained was composed of three phases: an upper oily phase (OP) containing the undigested species, an intermediate micellar phase (MP) containing digested and bioaccessible lipids, and a precipitate phase (PP) with insoluble compounds. The reaction was monitored by taking aliquots and their subsequent lipid extraction and analysis. ResultsPoorer digestibility for ARA and DHA oils was observed based on the percentage of the oily phase (26.7% and 20%, respectively) found compared to the glycerolysis product (GP) oily phase (13.9%). The highest micellar phase was found in the GP (approx. 83%). On the other hand, the monoglyceride (MAG) content was lower in the digestion product (DP) from ARA and DHA oils, 4.3% and 9.2%, respectively, compared to the MAG observed in the DP of GP (15%). ConclusionConsidering the percentage of oily phase, micellar phase, and the MAG content, it can be concluded that the GP is more digestible and ARA and DHA are more bioaccessible than in its precursor oils.

Bioaccessibility and antioxidant activity of fermented chrysanthemum rice wine on In vitro simulated digestion

The purpose of this study was to investigate the bioaccessibility of total phenolic (TPC), total flavonoid (TFC), chlorogenic acid and antioxidant activity in fermented chrysanthemum rice wine (FRW) under in vitro gastrointestinal digestion model compared with rice wine (RW). The fermented samples were digested and the bioactive components and antioxidant activity during gastric phase (GP) and intestinal phase (IP) were analyzed. The results showed that TPC, TFC, ferric reducing antioxidant power (FRAP), 2,2-diphenyl-1-picrylhydrazyl (DPPH), and oxygen radical absorbance capacity (ORAC) decreased during the gastrointestinal digestion stage. TFC was higher in FRW during in vitro gastrointestinal digestion stage and increased to a maximum of 0.483 mg/mL at IP stage. 2.2- azinobis-3- ethyl-benzothiazoline-6 - sulfonic acid (ABTS) reached its maximum value of 91.62% in the late stage of intestinal digestion. The hydroxyl radical scavenging activity (HRSA) increased to 77.94% in the IP-2 phase. In addition, a total of 158 (FRW) and 131 (RW) polyphenols, including flavonoids, isoflavones, phenols and coumarins, were detected and identified by Ultra-high performance liquid chromatography-tandem mass spectrometry (UPLC-MS) analysis. The biotransformation was carried out between the isomers of phenolic compounds in FRW, where 4,5-dicaffeoylquinic acid might be changed into neochlorogenic acid and chlorogenic acid. Correlation analysis showed that 46.15% of metabolites in FRW were positively correlated with the decrease of DPPH, FRAP and ORAC, while 53.85% were positively correlated with the increase of ABTS and HRSA. The results showed higher bioavailability and antioxidative activity in FRW after in vitro digestion.

Comparative efficacy of amino acid availability and peptidomic analysis of alternative proteins from different sources under dynamic in vitro protein digestion

The increasing global demand for animal protein highlights the critical necessity of exploring alternative protein sources. Accessing the nutritional characteristics of emerging alternative proteins is vital for food processing and consumer acceptance. This study investigated the amino acid availability and peptidomics profiles of plant- (soy), fungal- (filamentous fungus Fusarium venenatum), microalgae- (Nannochloropsis oculata), and insect-based (black soldier fly) proteins using an advanced dynamic in vitro digestion system, with whey protein as a reference. After gastric digestion, soy and mycelial proteins, despite displaying distinct microstructures, exhibited slightly higher protein digestibility levels of 28.79% and 26.36%, respectively, compared to whey protein (22.39%). However, following small intestinal digestion, whey protein (61.31%) significantly outperformed alternative proteins. Mycelial protein (43.71%) exhibited digestibility similar to soy protein (46.12%), markedly surpassing both microalgae protein (33.35%) and insect protein (26.58%). Notably, insect protein achieved an amino acid availability nearly approaching that of whey protein, underscoring its substantial proteolysis capability. Furthermore, microalgae protein produced the highest percentage and number of bioactive peptides under simulated digestion, suggesting potential health benefits such as angiotensin I-converting enzyme (ACE) and dipeptidyl peptidase-IV (DPP-IV) inhibitor activities, which could mitigate the risk of hypertension and Type 2 diabetes. Alternative proteins from different sources demonstrate diverse digestive mechanisms and proteolysis profiles, thereby bolstering their potential applications as nutritious food ingredients in the future.

Interactions of White Mugwort (Artemisia lactiflora Wall.) Extract with Food Ingredients during In Vitro Gastrointestinal Digestion and Their Impact on Bioaccessibility of Polyphenols in Various Model Systems.

The bioaccessibility of phytochemicals is an important factor for new functional food design. The interaction of white mugwort extract (FE) and food ingredients (coconut oil, egg white albumen, brown rice powder, inulin, and mixtures thereof) was determined after in vitro digestion to inform the development of a functional soup for an aging population. Coconut oil exerted a protective effect on polyphenols, showing the highest bioaccessibility (62.9%) and antioxidant activity after intestinal digestion (DPPH 12.38 mg GAE/g DW, FRAP 0.88 mol Fe(ll)/g DW). In contrast, egg white albumen had the most significant negative effect on the polyphenol stability, resulting in the lowest bioaccessibility (12.49%). Moreover, FE promoted the emulsion stability and delayed starch digestion by inhibiting amylase activity via non-specific polyphenol-protein interactions, resulting in a decrease in the total reducing sugars (TRS) released during digestion. It also limited the protein digestion, probably due to the complex formation of polyphenols and proteins, consequently reducing the bioaccessibility of both amino acids and polyphenols. These findings provide useful information for designing functional food products that could promote the bioaccessibility and bioactivity of natural extracts.

Hydrophobic solid lipid-based microparticles for the protection of gastric-sensitive hydrophilic active biomolecules for oral administration in the treatment of EPI

Exocrine Pancreatic Insufficiency (EPI), induced by conditions such as cystic fibrosis, chronic pancreatitis, and Crohn’s disease, is a frequently overlooked and underdiagnosed gastrointestinal disorder. It leads to inadequate intestinal digestion due to insufficient secretion of pancreatic juice, resulting in discomfort, pain, and ultimately severe malnutrition. Despite numerous treatments proving ineffective over the past three decades, a strictly hydrophobic solid lipid formulation, administered orally, is proposed in this study to restore digestive function. This technology relies on the hydrophobic nature of the matrix to physically protect the hydrophilic active principle from the gastric environment while enabling its immediate release in the duodenum by targeting the amphiphilic nature of bile salts. Results demonstrate that this formulation effectively protects an acid-sensitive active ingredient during gastric passage (Simulated Gastric Fluid or SGF), facilitating its rapid release upon entering an artificial duodenal environment (Simulated Intestinal Fluid or SIF). Furthermore, it has been demonstrated that the preservation of a protein-based active ingredient extends beyond its primary protein structure to include its functional aspects, such as enzymatic activity. This drug delivery technology could enable the protection of hydrophilic active biomolecules, such as pancreatin, which are sensitive to gastric acidity, while promoting their immediate release upon contact with bile salts in the proximal duodenum, with the ultimate goal of correcting the digestive defect induced by EPI.

Bioconversion of sugar beet molasses into functional exopolysaccharides by beet juice-derived lactic acid bacteria

Sugar beet molasses, a sugar-rich byproduct of sugar beet industry, have great potential as a biorefinery feedstock for the production of value-added bio-products by microbial fermentation. The production of functional exopolysaccharides (EPS) by lactic acid bacteria (LAB) represents a promising strategy for valorizing sugar processing waste. This study screened and identified high-efficiency EPS-producing LAB isolates from beet juice. Among the 32 isolates, six LAB strains including Limosilactobacillus fermentum YL7, Lactiplantibacillus plantarum YL4, TC10, and CJ10, Leuconostoc mesenteroides TCT3 and TCT4, exhibited efficient bio-conversion of beet molasses to LAB-EPS, with yields varying from 13.96 to 22.26 g/L. Antioxidant activity analysis revealed that EPS from these strains displayed significant scavenging activities against ABTS+, DPPH, and -OH radicals. Notably, EPS produced by L. plantarum TC10 and L. fermentum YL7 exhibited superior ABTS + scavenging capacity, with rates up to 99.48% and 95.89% at 4 mg/mL, respectively. Additionally, EPS from strains YL4, YL7, TCT3 and TCT4 showed significant antibiofilm activity against S. aureus and E. coli, with EPS-YL7 inhibiting S. aureus biofilm formation by up to 90.49% at 8.0 mg/mL. Furthermore, EPS from strains TCT4 demonstrated great tolerance to digestive fluid compared to EPS from other strains, with a retention rate of 72% at the end of intestinal digestion. These findings suggest that EPS-producing LAB strains from beet juice can efficiently convert beet molasses into valuable EPS utilized as functional food ingredients.

In vitro digestion and fermentation of the whole goji berry: Bioactive ingredients change and impacts on human gut microbiota.

Goji berry (Lycium barbarum L.) is a nutrient-rich fruit and has received enormous interest for its health benefits. The beneficial effects of goji berry are linked to the absorption of bioactive compounds within the gastrointestinal digestion process and colon fermentation. Nonetheless, how certain bioactive compounds were released, and metabolism changed of the consumption of whole goji berries were still unclear. Therefore, the present study aimed to evaluate the digestion characteristics of key bioactive compounds in whole goji berries with an in vitro digestion model, and the effects of whole goji berries on the structure of gut microbiota were also investigated. Results showed that a significant release of carbohydrates during the digestion process, peaking within the first 15min of the intestinal phase (421.4±5.82mgGE/g, dry weight, respectively), was observed, and the phenolic release reached the highest in the first 15min of the gastric phase. Meanwhile, the bioaccessibilities of phenolic compounds and carbohydrates were determined to be 63.87% and 80.40%, respectively, after intestinal digestion. In addition, the undigested fractions of goji berries could be further fermented to produce short-chain fatty acids, which decreased the colon pH value (from 7.38 to 6.71) as well as the Firmicutes/Bacteroidetes ratio. Moreover, the goji berries regulated the composition of gut microbiota by promoting beneficial bacteria such as Bacteroides, Parabacteroides, and Paraclostridium, whereas inhibiting the proliferation of harmful bacteria (e.g., Fusobacterium). Our results indicated that the goji berry exhibited significant bioactivity during the digestion and fermentation stage and might provide some new insights into the utilization of goji berries in healthy food processing.

Detailed Analysis of Prebiotic Fructo- and Galacto-Oligosaccharides in the Human Small Intestine.

Galacto-oligosaccharides (GOS) and fructo-oligosaccharides (FOS) are food ingredients that improve human health, but their degradation throughout the human small intestine is not well understood. We studied the breakdown kinetics of FOS and GOS in the intestines of seven healthy Dutch adults. Subjects were equipped with a catheter in the distal ileum or proximal colon and consumed 5 g of chicory-derived FOS (degree of polymerization (DP) DP2-10), and 5 g of GOS (DP2-6). Postprandially, intestinal content was frequently collected until 350 min and analyzed for mono-, di-, and oligosaccharides. FOS and GOS had recoveries of 96 ± 25% and 76 ± 28%, respectively. FOS DP ≥ 2 and GOS DP ≥ 3 abundances in the distal small intestine or proximal colon matched the consumed doses, while GOS dimers (DP2) had lower recoveries, namely 22.8 ± 11.1% for β-D-gal-(1↔1)-α-D-glc+β-D-gal-(1↔1)-β-D-glc, 19.3 ± 19.1% for β-D-gal-(1 → 2)-D-glc+β-D-gal-(1 → 3)-D-glc, 43.7 ± 24.6% for β-D-gal-(1 → 6)-D-gal, and 68.0 ± 38.5% for β-D-gal-(1 → 4)-D-gal. Lactose was still present in the distal small intestine of all of the participants. To conclude, FOS DP ≥ 2 and GOS DP ≥ 3 were not degraded in the small intestine of healthy adults, while most prebiotic GOS DP2 was hydrolyzed in a structure-dependent manner. We provide evidence on the resistances of GOS with specific β-linkages in the human intestine, supporting the development of GOS prebiotics that resist small intestine digestion.

Upgrading In Vitro Digestion Protocols with Absorption Models

Intestinal digestion and absorption are complex processes; thus, it is a challenge to imitate them realistically. There are numerous approaches available, with different disadvantages and advantages. The simplest methods to mimic absorption are the non-cell-based transport models but these lack important characteristics of enterocytes of the intestine. Therefore, the most often used method is to measure absorption through viable mammalian cells (most commonly Caco-2 cells, cultured on membrane insert plates), which not only assures the incorporation of brush border enzymes (responsible for the final digestion of peptides and disaccharides), it also simulates the absorption process. This means that influx/efflux transporter-facilitated transport, carrier-mediated transport, endocytosis, and transcytosis is also imitated besides passive diffusion. Still, these also lack the complexity of intestinal epithelium. Organoids or ex vivo models are a better approach if we want to attain precision but the highest accuracy can be achieved with microfluidic systems (gut-on-a-chip models). We propose that more research is necessary, and food absorption should also be studied on gut-on-a-chips, especially with fragmented organoids. Our review supports the choices of a proper intestinal epithelium model, which may have a key role in functional food development, nutrition studies, and toxicity assessment.

PSV-29 In vitro digestibility and in situ degradability of lobster and mixed crab shell waste material

Abstract The objective of this research was to determine the in situ and in vitro degradability of lobster shell waste meal (LM) and crab shell waste meal (CM). Lobster and crab harvest are major industries within the New England states and the Maritime provinces. Harvest of the American lobster amounts to 54,643 tons caught and processed in 2020 in the New England states. The Atlantic Red Crab annual quota is around 1,814 tons. The Jonah Crab amounts to 5,725 tons. Due to the significant harvest, there is a resulting increase in byproducts and wastes at processing facilities providing potential feedstuffs for cattle. For both experiments, LM and CM were compared with soybean (SBM) and blood meals (BM). In experiment 1, 0.5 g of each meal were added to an artificial rumen incubator (Daisy, Ankom technologies) and DM degradability over 48 h was measured. In experiment 2, ruminally-cannulated Holstein cows (n = 4) in a 4 × 4 Latin square, had 5 g of sample were placed in Dacron bags in the dorsal rumen. Bags were in duplicate and removed at 2, 4, 8,12, 24, and 48 h time points. Eight bags were removed at 12 h for use in the in vitro intestinal degradability measurement using the modified three-step technique. Contrasts were: SBM vs. BM+LM+CM (SBM vs others), BM vs. LM+CM, and LM vs. CM. In experiment 2, 0 h bags served as a determination of fraction A, while the 48 h bags served as fraction C. Fraction B = 100% - (fraction A + fraction C). Degradation rate (kd) was calculated by converting % CP degraded from 2 to 24 h to Ln and then calculating the slope. In experiment 1, DM degradation was 45.8, 43.8, 76.4 and 100.1 % for SBM, BM, LM, and CM respectively; SBM vs others (P < 0.01), BM vs. LM + CM (P < 0.01), and no difference between LM vs. CM. Fraction A (CP) was 9.9, 8.1, 4.2, and 4.8% respectively; with SBM vs. others (P < 0.03), BM vs. LM+CM (P < 0.01), and no difference between LM vs CM. Fraction B (CP) was 76.2, 62.2, 28.9, and 42.6% respectively; with SBM vs. others (P < 0.01), BM vs. LM + CM (P < 0.01), and LM vs. CM (P < 0.10). Fraction C (CP) was 4.41, 30.8, 46.8, and 37.5% respectively; with SBM vs. others (P < 0.01), BM vs. LM + CM (P < 0.03), and LM vs. CM (P < 0.08). Intestinal CP digestibility was 56.2, 64.7, -5.83, and 10.5% respectively, with SBM vs others (P < 0.01), BM vs LM+CM (P < 0.01), and no difference between LM and CM. Results of these studies indicated that LM and CM may have some benefits in cattle diets, but feeding studies should be conducted.

487 Rumen degradation, N-To-Energy Synchronization, and Intestinal digestion Study in dairy cows: Effect of oat varieties and types (feed type vs. milling type)

Abstract This study aimed to determine the impact of four oat varieties and types (feed type vs. milling type) on the rumen degradation kinetics of nutrients, intestinal digestion of nutrients, and N to energy synchronization. Twelve samples [4 varieties (Arborg, Haymaker, Nasser, Summit) × 3 harvested years (2018, 2019, 2020)] were used for in situ rumen incubation analysis, three-step in vitro analysis, and available N to energy synchronization evaluations. The experiment design was RCBD design (oat varieties as a fixed effect and harvested year as a random block effect). Statistical analysis was performed by MIXED procedure model of SAS 9.4, and significance was declared at P < 0.05 and tendency at 0.05 ≤ P < 0.10. Results showed that Haymaker and Arborg oat had higher rate of degradation of degradable fractions (Kd) of dry matter (DM), crude protein (CP), and starch than that of Nasser oat (P < 0.05). Nasser oat had greatest rumen bypass dry matter (BDM, g/kg DM), and rumen bypass feed starch (BST, g/kg DM) in these four varieties (P < 0.05) while the effective degradability of dry matter (EDDM, g/kg DM), effective degradability of feed crude protein (EDCP, g/kg DM), and effective degradability of feed starch (EDST, g/kg DM) of Nasser oat were least among varieties (P < 0.05). There were significant differences in BDM, EDDM, %BST, and EDST between milling oat and feed oat. For the intestinal nutrient digestibility, Summit oat had greatest intestinal digestibility of rumen bypass dry matter (%dBDM) among four varieties (P < 0.05), and the value of intestinal digestible rumen bypass dry matter (IDBDM, g/kg DM) of Summit was greatest in these varieties, which has greater IDBDM (g/kg DM) content than that of Nasser oat (P < 0.05). Nasser oat also had the least total digestible dry matter (TDDM, g/kg DM) in these varieties (P < 0.05). Summit oat had similar intestinal digestibility of rumen bypass protein (%dBCP) with Haymaker and Nasser oat but had greater %dBCP content than that of Arborg oat (P < 0.05). Nasser oat had greater intestinal digestible rumen bypass protein (%IDBCP, % of CP) in these four varieties (P < 0.05), while its value of total digestible protein (TDCP, g/kg DM) was the smallest and the TDCP content of Nasser oat was less than Haymaker oat (P < 0.05). Summit and Arborg oat had greater total digestible feed starch (TDST) than that of Nasser oat (P < 0.05). Significant differences were found on %dBDM, IDBDM, TDDM, and TDST between the feed type and milling type oat (P < 0.05). Haymaker oat had similar ratio of N to organic matter (OM) of the oat (N/OM) with Nasser oat but had greater N/OM content than that of Arborg and Summit oat (P < 0.05).

90 Awardee Talk: Shedding light into the black box: The dual-flow continuous culture system and ruminal fermentation

Abstract Nutrients derived from ruminal fermentation supply a substantial amount of metabolizable nutrients for ruminants. These include amino acids, carbohydrates, fatty acids, vitamins, and fermentation end products, such as ammonia and volatile fatty acids. Furthermore, ruminal fermentation modifies dietary nutrients in such a way that nutrients reaching the small intestine for absorption may substantially differ from those being consumed in the diet. Therefore, understanding ruminal fermentation kinetics and quantification of nutrients flowing out of the rumen is an important aspect of ruminant nutrition. Accurate quantification of these nutrients, using in vivo experiments, is laborious, costly, and invasive, requiring surgical procedures such as ruminal, abomasal, and intestinal cannulas. To decrease the time and cost of experiments as well as the use of animals, in vitro methodologies are important tools in ruminant nutrition. Therefore, the objectives of this presentation are i) describe different in vitro methodologies, ii) discuss the advantages of in vitro methodologies, iii) discuss shortcomings of in vitro methodologies, and iv) describe potential developments that may improve in vitro methodologies. Having been used for decades, in vitro methodologies such as pure, batch, and continuous cultures have been well documented to investigate a wide array of aspects of nutrition, including the effects of different dietary compositions, individual fermentation end products, and impacts on the microbiome. However, both batch and pure cultures can result in a build-up of end products that may inhibit fermentation. Continuous culture, however, allows for the removal of end products but, similar to pure and batch cultures, is applicable only to ruminal fermentation and cannot provide information regarding intestinal digestion. The dual-flow continuous culture system (DFCC), developed in the 1970s and used by various laboratories in the USA and Europe consists of fermentation vessels of approximately 1.5 L that are capable of simulating ruminal fermentation for periods longer than 10 d. It has been extensively used and evaluated by meta-analyses. When compared with other in vitro methodologies, the DFCC has longer fermentation time, larger volume, and the possibility of sampling from the liquid and the solid flows. When compared with in vivo experiments the DFCC is faster, less costly, less invasive, allows for greater range of treatments, allows for more controlled condition, and isolates ruminal function. Limitations of the DFCC include it does not predict in vivo response, it assumes equal saliva flow and concentration, no effects of intake, no ruminal absorption, less retention of protozoa, possible differences in microbiome, and limited gas emission data. Therefore, while in vitro methodologies provide useful data into the field of ruminant nutrition, some in vitro methodologies are more robust than others. Furthermore, in vivo experiments are still the ideal approach for assessing nutrient utilization and necessary to evaluate animal responses.