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At least 1,063 records · Page 59Linked to original sources
PubMed1995

Effect of high copper dosing on hemicellulose digestibility in cecectomized cockerels.

A precision-fed cockerel digestibility assay using ground corn cobs was conducted to test a theory that birds fed pharmacological doses of Cu (250 mg Cu/kg diet) may exhibit a higher hemicellulose digestibility due to increased release of lysosomal enzymes in the bile. Finely ground corn cobs were crop intubated into adult cockerels that had been pretested on diets containing either 0 or 250 mg Cu/kg (from CUSO4.5H2O). Copper-loaded cockerels showed higher (P < .05) true dry matter digestibility, hemicellulose digestibility, and TMEn than the control cockerels. True dry matter digestibility of corn cobs was 11.1% in Cu-loaded cockerels, which was nearly double that observed (6.2%) in control cockerels. Hemicellulose digestibility also increased from 22.1% in control cockerels to 36.6% in Cu-loaded cockerels. Copper-loaded cockerels obtained some TMEn (117.7 kcal/kg) from corn cobs, whereas the control cockerels obtained no TMEn from the corn cob intubation. The preliminary results presented herein demonstrate that pharmacological doses of dietary Cu may improve hemicellulose digestibility, which may in part explain the growth-promoting effect of Cu.

Animal Nutritional Physiological Phenomena↗
PubMed1996

Bioavailability of digestible lysine in heat-damaged soybean meal for chick growth.

Previous experiments indicated that true digestible Lys values for soybean and cottonseed meals obtained with the precision-fed cecectomized rooster assay were accurate estimators of Lys bioavailability for chick growth. This study was conducted to determine whether the digestible Lys in overheated soybean meal (SBM) was totally bioavailable for protein synthesis. Soybean meal alone or mixed with dextrose (SBM:dextrose ratio = 3:1) was autoclaved at 114 C and 97 kPa for 0 to 60 min. True digestibility of Lys in SBM was determined using the precision-fed cecectomized rooster assay. Bioavailability was then assessed by chick growth assay using purified crystalline amino acid diets deficient in Lys that were supplemented with varying levels of crystalline L-Lys.Cl or a SBM. Multiple regression slope-ratio methodology indicated that the digestible Lys in unautoclaved SBM was 100% bioavailable. For SBM autoclaved for 40 or 60 min and SBM-dextrose autoclaved for 20 min, bioavailability of digestible Lys based on weight gain or carcass Lys gain was 81 to 87% and significantly less (P < 0.05) than 100%, whereas bioavailability values based on feed efficiency and carcass N gain did not differ (P > 0.05) from 100%. Bioavailability values for digestible Lys in SBM:dextrose autoclaved for 30 min ranged from 55 to 73% for all performance criteria. Partitioning the response criteria, so that only the response to the supplemental Lys source (not the basal diet) was being evaluated, increased the bioavailability values for all treatments except SBM:dextrose autoclaved for 30 min. The results of this study indicated that digestible Lys in severely heat-damaged SBM measured by the precision-fed cecectomized rooster assay was not totally bioavailable for protein synthesis.

Animal Feed↗
PubMed1999

Seasonal variation of xanthine oxidoreductase activity in the digestive gland cells of the mussel Mytilus galloprovincialis: a biochemical, histochemical and immunochemical study.

The activity and the tissue distribution of the oxygen radical producing enzyme xanthine oxidoreductase (XOR) were measured in the digestive gland of the common marine mussel Mytilus galloprovincialis Lmk along an annual cycle. No xanthine oxidase (XOX) activity could be measured, the enzyme only displaying xanthine dehydrogenase (XDH) activity in all the cases. This is interpreted as a mechanism to avoid the harmful effects of the oxygen radicals that would be produced by XOX during periods following anoxic conditions at low tide. The highest XDH activities coincided with the late spring/early summer months, the activity maxima being recorded from May to July. Histochemically XOR activity was very pronounced in duct and stomach epithelial cells as well as in the surrounding connective tissue and hemolymph vessels, the activity increasing towards the summer months. These seasonal variations in XDH or XOR activities are possibly linked to hormonal changes governing the reproductive cycle and to changes in food availability. The localization of the protein in the connective tissue lining the hemolymph vessels was confirmed immunohistochemically using a polyclonal antibody against rat liver protein that cross-reacted specifically with a polypeptide of 150 kDa of molecular mass in homogenates of the digestive gland. This polypeptide was linked to cytosolic fractions isolated by differential centrifugation from mussel digestive glands. In paraffin sections the antibody labeled the digestive cells of digestive tubules, as well as the connective tissue surrounding the hemolymph vessels, gonadal follicles, digestive epithelia and certain protozoan parasites. Taken together our results suggest that in the digestive gland of bivalve molluscs XOR is involved in the metabolism of purines and in the scavenging of oxygen free radicals.

Animals↗
PubMedDate not supplied

The effect of ageing on nutrient digestibility by cats fed beef tallow-, sunflower oil- or olive oil-enriched diets.

Nutrient digestibility and absorption decline with age in several mammalian species. The aim of this study was to compare apparent fat digestibility of different dietary fats in young and senior cats. Three diets enriched with either beef tallow (high in saturated fatty acids), olive oil (high in monounsaturated fatty acids) or sunflower oil (high in polyunsaturated fatty acids) were fed to 6 young (3.0+/-0.9y) and 6 senior (11.6+/-1.4y) cats at 300kJ metabolisable energy/kgBW0.75/d in a 3*3 Latin square design. Food and faecal samples collected over two consecutive 7d periods were analysed for fat, protein, moisture, ash, gross energy and fatty acid content. Apparent digestibilities of fat and energy were significantly lower (P=0.03) in senior cats compared to young cats (fat: 0.922 compared to 0.944; energy: 0.848 compared to 0.885, for senior and young cats, respectively) in all three diets. Senior cats exhibited a lower apparent digestibility for all fatty acid groups compared to the younger cats (saturated: 0.932 compared to 0.952; monounsaturated: 0.964 compared to 0.982; polyunsaturated: 0.980 compared to 0.987, for senior and young cats, respectively). Saturated fatty acids had the lowest apparent digestibility in both young and senior cats, and shorter chain fatty acids were digested more easily than the longer chain fatty acids. These results suggest that the age-related reduction in apparent fat digestibility was a general phenomenon affecting all fatty acids, and was not due to one particular fatty acid group.

Aging↗
PubMed2001

Benzo[a]pyrene and zinc solubilization by digestive fluids of benthic invertebrates--a cross-phyletic study.

Contaminant bioavailability via digestive exposure was examined for 18 species of marine benthic invertebrates, using incubation of digestive fluids with sediments that were spiked with either radiolabeled benzo-[a]-pyrene (BaP) or zinc. Interphyletic trends in contaminant solubilization were compared with measures of digestive biochemistry, including enzyme activities, surfactancy, pH, and fluid phase organic carbon, amino acids, and lipids. Contaminant solubilization ranged from values equal to that of a seawater control to as much as an order of magnitude higher but were lower than those obtained with commonly used chemical extractants. Digestive fluids from echinoderms and a cnidarian tended to be relatively weak, those from polychaetes and echiurans were relatively strong, and those from taxa such as sipunculans and mollusks were intermediate. These trends correlated strongly with concentrations or activities of digestive biochemicals but not with pH. These correlations are consistent with previous work on mechanisms of digestive solubilization of polycyclic aromatic hydrocarbons (PAH) and metals, though strong covariance among digestive parameters does not allow this approach to be used for identification of specific mechanism(s).

Animals↗
PubMedDate not supplied

In vitro determination of the release kinetics of peptides and free amino acids during the digestion of food proteins.

The kinetics of peptide release during in vitro digestion of 4 protein sources (casein, cod protein, soy protein, and gluten) were investigated. Samples were sequentially hydrolyzed with pepsin (30 min) and pancreatin (2, 4, or 6 h) in a dialysis cell with continuous removal of digestion products. Nondialyzed digests were fractionated by ion-exchange chromatography and ultrafiltration. Animal proteins were digested at a greater rate than plant proteins. Target amino acids of specific enzymes appeared more rapidly in the dialyzed fractions when compared to other amino acids. Throughout the hydrolysis, nondialyzed digests contained a higher proportion of peptide mixtures with basic-neutral properties. Except for gluten, peptide fractions with molecular weights that exceeded 10 kDa (basic-neutral, BN > 10) were rapidly hydrolyzed during the first 2 h of pancreatin digestion. The kinetics of release and the composition of peptide fractions were different when the protein sources were compared. The analysis of amino acids revealed that threonine and proline proportions were relatively high in BN > 10 and in peptide fractions with molecular weight between 10-1 kDa (BN 10-1), while tyrosine, phenylalanine, lysine, and arginine predominated in the low molecular weight (<1 kDa) fractions. More resistant peptides were generally rich in proline and glutamic acid. The role of in vitro digestion assays in dietary protein quality evaluation is discussed.

Amino Acids↗
PubMed2006

Comparison of ileal digested production of parental rice and rice genetically modified with cowpeas trypsin inhibitor.

OBJECTIVE: To compare the ileal digestibility of protein and amino acids in parental rice and rice genetically modified with sck gene. METHODS: Six experimental swines were surgically fixed with a simple T-cannula at the terminal ileum and fed with parental rice and rice genetically modified with sck gene alternately. The ileum digesta were collected and analyzed for determination of apparent and true digestibility of protein and amino acids. RESULTS: The apparent and true digestibility of protein was similar in these two types of rice. Except for the apparent digestibility of lysine, there was no difference in the apparent and true digestibility of the other 17 amino acids. CONCLUSION: The digestibility of protein and amino acids is not changed by the insertion of foreign gene, so it can meet the request of "substantial equivalence" in digestibility of protein and amino acids.

Amino Acids↗
PubMed1988

Microscopic effects of predator digestion on the surfaces of bones and teeth.

Concentrations of small fossil mammals are frequently encountered in Cenozoic deposits, but the causes for such accumulations have seldom been determined. In many cases the tooth, jaw, and limb fragments appear to be well-preserved under light microscopy, and it is difficult to differentiate damage due to predator digestion from breakage and abrasion due to physical agents. In order to find more specific evidence of predator digestion, we used a scanning electron microscope (SEM) to examine the surface microstructure of bones and teeth consumed by Bubo virginianus (great horned owl) and Canis latrans (coyote), which prey upon similar species. Effects of digestion were found on all the digested bones and teeth examined. The effects on bone include distinctive sets of pits and fissures, dissolution, and physical polishing. The pits and fissures are apparently caused by solution that commences in canals beneath the surface of the bone. The most conspicuous effects on teeth are island-like pillars of dentin surrounded by deep solution fissures. The effects of digestion by coyote and owl are fundamentally the same but differ in degree of development. Bone digested by the owl shows a greater degree of polishing and rounding of edges but has less extensive fissuring. Wide variation in the degree of surface damage occurs in bones digested by the coyote, even within a single fecal pellet.

Animals↗
PubMed1985

[Carbohydrate digestion in monogastric animals].

The main dietary carbohydrates are starch, cell wall polysaccharides (cellulose, hemicelluloses and pectins), some monosaccharides (glucose, fructose, galactose, etc.) and oligosaccharides (sucrose, lactose, alpha-galactosides, etc.). Recent analytical methods applied to these substances are described and criticized. A-type starches (cereals), cooked starches and some oligosaccharides are mainly digested in the small intestine of monogastric animals by enzymes of the salivary glands, pancreas and intestinal brush border. The total digestibility of these carbohydrates is almost 100%, whereas it is less than 70% for B-type starches (ex. potato). Cellulose, hemicelluloses, pectins and some oligosaccharides are partly digested by the microflora of the large intestine. Fiber total digestibility varies considerably and depends on the nature of the fiber and the animal species. It is less than 10% in chickens, whereas pigs seem to digest fibers as well as sheep. Hydrothermic treatments usually have no effect on starch digestibility but can be used for B-type starches. Some chemical treatments may improve fiber digestibility in monogastric animals.

Animals↗
PubMed1979

[Digestive diseases morbidity and need for medical care requirements. Prevalence study of declared symptoms and demand for medical care in a French "department" (author's transl)].

A survey on digestive morbidity and demand for medical care in a pilot area concerned 3504 persons, eighteen years old and over; 69.3 p. 100 of them reported that they had been affected by one or several digestive symptoms during the previous year. However, it concerns mostly just common symptoms, probably benign, observed in all age groups; only 9.4 p. 100 of those complaining (half of them being old persons) reported disorders which can be suspected as serious ones. Among the subjects presenting symptoms, there is a majority of women, of urban population, of higher educational levels and higher social classes. During this year 18.9 p. 100 of the total population sought medical advice for digestive symptoms, the average number of consultations being 0.7 for every subject. This demand is related to the age, the number and gravity of the complaints, and to the presence of a digestive history; 24.5 p. 100 of the subjects used self medication: this is related to the perception of benign disorders, to digestive history, sex and social class: factory workers, farm workers and self-operating farmers are using this least. Women complain of digestive disorders more often than men and practice self medication more frequently. They do not report serious symptoms or a history of digestive disease more often than men, nor do consult doctors more frequently.

Adult↗
PubMed1980

[Comparison of goats and sheep with respect to the ingestion, digestibility and nutritive value of various diets].

The voluntary food intake, organic matter, crude protein and crude fiber digestibility and nitrogen balance of 23 diets have been measured simultaneously using 5 to 7 wethers and 5 to 7 castrated billy-goats in digestibility trials. The goats ate more than the wethers (58 vs 46 g DM/kg W0.75). The digestibilities obtained for goats were highly correlated with those obtained for wethers, and the mean values were similar in both species: Organic matter: digestion coefficient (CUD)goats = 1.22 CUDwethers -14.5 r = 0.93 Crude protein: digestion coefficient (CUD)goats = 1.07 CUDwethers -4.8 r = 0.94 Crude fiber: digestion coefficient (CUD)goats = 0.56 CUDwethers +29.6 r = 0.78 The mean nitrogen balance for goats (226 mg/kg W0.75) was significantly higher than that of wethers (152 mg/kg W0.75). Based on the regression equations for each species, the calculated efficiency of proteins digestible in the intestine (PDI) was 55 p. 100, the endogenous urinary nitrogen 160 mg/kg W0.75 and the nitrogen maintenance requirement 1.8-1.9 g of PDI/kg W0.75.

Animal Feed↗
PubMed1982

[Determination of the digestibility of lignocellulose material using the bag (nylon bag) method].

A trial was performed on wethers to study the digestibility of various lignocellulose materials (LCM) by the nylon bag method. The animals were fed good meadow hay ad lib. with unlimited access to water and mineral lick. The trial showed that LCM digestibility was not influenced by different weights of substrate sample. However, digestibility increased with the time for which the LCM were left to ferment in rumen. Almost 90% or more dry matter of the different substrates (pure sulphate cellulose, barley straw and treated beech sawdust) was digested within 48-hour fermentation in rumen. The situation is similar when the substrates are left to ferment in vitro for 96 hours. The high correlation coefficients calculated from the digestibility values of the substrates in vitro and in vivo testify to this fact. The only exception is untreated beech sawdust in which no such a high correlation was found, mainly owing to its low digestibility. However, this should be verified in other kinds of untreated wood (aspen, maple, ash), but with a higher digestibility. It should be stated that silk with a 50 mu mesh is the best material for the production of the bags.

Animal Feed↗
PubMed1980

[Regulation of the processes of dipeptide and saccharose digestion and hexose absorption in the canine small intestine].

The total amount of digested saccharose increased under the effect of acetylcholine, noradrenaline, ornide, whereas the total amount of digested dipeptides increased under the effect of atropine. The decrease of the total amount of digested saccharose occurred under the effect of atropine and of digested dipeptides under the effect of acetylcholine, noradrenaline, ornide. The effects of these agents on digestion in the cavity and on the small intestine walls were not similar. The resorption of hexose formed during digestion of saccharose depended on the total amount of the digested saccharose.

Animals↗
PubMed1996

Digestion in the newborn.

Although the various aspects of digestion in the newborn have been studied for decades, we still lack quantitative information about the contribution of individual enzymes to the overall process. The information to date indicates that in spite of immaturity of many of the classical digestive mechanisms of the adult, the infant uses a number of compensatory systems to achieve adequate digestion of nutrients (Fig. 1). Thus, whereas in the infant gastric proteolysis is probably extremely limited, intestinal protein digestion is adequate. Although starch supplements are better tolerated in breast-fed infants, because of the compensation provided by human milk amylase, the infant is able to digest lactose and short-chain glucose polymers with endogenous brush border enzymes. Fat digestion is markedly aided by gastric lipase and, in breast-fed infants, the bile salt-dependent lipase of human milk. Thus, in the infant, gastric lipolysis is quantitatively much more significant than in adults. The absorption of human milk whey proteins (and probably also cow milk proteins) is probably associated more with the highly glycosylated form of these proteins than with immaturity of neonatal digestive enzymes.

Adult↗
PubMed1995

Digesta passage and functional anatomy of the digestive tract in the desert tortoise (Xerobates agassizii).

The herbivorous tortoise Xerobates agassizii contends with large fluctuations in the quality and abundance of desert pastures. Responses to grass (Schismus barbatus), herbage (Sphaeralcea ambigua) and pelleted diets were studied in captive animals. Digestive anatomy was investigated in wild tortoises. Cornified esophageal epithelia and numerous mucus glands along the digestive tract indicated a resistance to abrasive diets. Gastric contents were acidic whereas hindgut digesta were near neutral pH. The colon was the primary site of fermentation with short-chain fatty acids mainly comprised of acetate (69-84%), propionate (10-15%) and n-butyrate (1-12%). Fibre digestion was extensive and equivalent to 22-64% of digestible energy intakes. Large particles of grass (25 mm; Cr-mordants) were excreted as a pulse but retained longer than either fluids (Co-EDTA) or fine particles (2 mm; Yb). Patterns of marker excretion suggested irregular mixing of only the fluid and fine particulate digesta in the stomach and the colon. Mean retention times of Cr-mordants were 14.2-14.8 days on the grass and high-fibre pellets. Intakes of grass were low and accompanied by smaller estimates of digesta fill than for the high-fibre pellets. Digestive capacity was large and estimated at 11-21% of body mass on these diets. The capacious but simple digestive anatomy of the tortoise may provide the greatest flexibility in utilizing a variety of forages in its unreliable habitat.

Animals↗
PubMed2000

Integration of immobilized trypsin bead beds for protein digestion within a microfluidic chip incorporating capillary electrophoresis separations and an electrospray mass spectrometry interface.

A microfluidic device is described in which an electrospray interface to a mass spectrometer is integrated with a capillary electrophoresis channel, an injector and a protein digestion bed on a monolithic substrate. A large channel, 800 microm wide, 150 microm deep and 15 mm long, was created to act as a reactor bed for trypsin immobilized on 40-60 microm diameter beads. Separation was performed in channels etched 10 microm deep, 30 microm wide and about 45 mm long, feeding into a capillary, attached to the chip with a low dead volume coupling, that was 30 mm in length, with a 50 microm i.d. and 180 microm o.d. Sample was pumped through the reactor bed at flow rates between 0.5 and 60 microL/min. The application of this device for rapid digestion, separation and identification of proteins is demonstrated for melittin, cytochrome c and bovine serum albumin (BSA). The rate and efficiency of digestion was related to the flow rate of the substrate solution through the reactor bed. A flow rate of 1 or 0.5 microL/min was found adequate for complete consumption of cytochrome c or BSA, corresponding to a digestion time of 3-6 min at room temperature. Coverage of the amino acid sequence ranged from 92% for cytochrome c to 71% for BSA, with some missed cleavages observed. Melittin was consumed within 5 s. In contrast, a similar extent of digestion of melittin in a cuvet took 10-15 min. The kinetic limitations associated with the rapid digestion of low picomole levels of substrate were minimized using an integrated digestion bed with hydrodynamic flow to provide an increased ratio of trypsin to sample. This chip design thus provides a convenient platform for automated sample processing in proteomics applications.

Animals↗
PubMed2005

Short-term and long-term effects of increasing temperatures on the stability and the production of volatile sulfur compounds in full-scale thermophilic anaerobic digesters.

This study compares the effect of a rapid increase of the digester temperature (from 54 degrees C to 58 degrees C in 2 weeks) with a slow increase (from 53.9 degrees C to 57.2 degrees C at a rate of 0.55 degrees C per month) on full-scale thermophilic anaerobic digestion at Hyperion Treatment Plant. The short-term test demonstrated that rapidly increasing the digester temperature caused elevated production of volatile sulfur compounds, most notably methyl mercaptan, but volatile solids destruction and methane production were not significantly affected. The increase of the volatile fatty acid to alkalinity ratio from 0.1 to over 0.3 indicated a transient change in digester biochemistry, which was reversed by lowering the temperature. In the long term-test, a slow increase of digester temperature, the production of hydrogen sulfide increased above temperatures of 56.1 degrees C, but was controlled by increased injection of ferrous chloride. Methyl mercaptan was detected in trace amounts at the highest temperature tested (57.2 degrees C). This test showed insignificant effects on other digestion parameters, although some temperature-independent changes were observed that could have been seasonal effects over the year that the long-term test lasted. Thus a slow temperature increase was preferable. This observation contrasts with previous results showing the desirability of a rapid temperature rise to first establish a thermophilic culture when converting from mesophilic operation. Further research is warranted on temperature limits and process changes to optimize thermophilic anaerobic digestion.

Adaptation, Physiological↗
PubMed2003

Comparison of automated in-gel digest methods for femtomole level samples.

A comparison of automated in-gel digestion methods for low picomolar to femtomolar levels of protein is presented. Gel spots with 4 pmol to 120 fmol of protein were stained with either Coomassie colloidal blue or SYPRO Ruby and digested using an automated platform. The sequence coverages and average peak intensities obtained from a matrix-assisted laser desorption/ionization-mass spectrometry (MALDI-MS) analysis are compared. Results show that methods using an acetonitrile extraction or digest times greater than the standard 4 h give no significant increase in peptide sequence coverage for automated digestion of low protein level samples. It is also shown that digests from SYPRO Ruby-stained gels show a greater improvement upon ZipTip cleanup than digests from Coomassie colloidal blue-stained gels. The digests from SYPRO Ruby-stained gels are also shown to give a higher average peptide intensity if a method with minimal gel plug washing is used.

Automation↗