Fiber Passage Research Articles

Role of Insoluble Fiber on Gizzard Activity in Layers

Effect of access to wood shavings on gizzard activity was examined for birds fed pelleted wheat and oat diets with or without whole cereal inclusion. Layers on litter floor fed wheat diets with access to coarse wood shavings showed up to 60% higher weight of the gizzard and its content than caged layers fed the same diets without access to wood shavings. No such effect was found by feeding oat diets. Thus, a significant interaction was found, indicating that the appetite for wood shavings may be dependent of fiber level of the diet. Appetite for wood shavings and paper was examined for birds fed wheat and oat diets in 2 other experiments. The intake of wood shavings and paper by birds fed a wheat-based diet was numerically twice as high as in birds fed an oat-based diet. However, the individual variation was remarkably high. Neutral detergent fiber (NDF) concentration in the gizzard of birds fed the oat diet was up to twice (P < 0.05) the fiber concentration in the gizzard of birds fed the wheat diet. Passage of structural fibers through the gizzard and the appetite for feathers in the absence of structural fibers were also studied in an experiment using diets based on rice and casein. Coarse fiber structures were observed to accumulate in the gizzard. In the absence of fiber, birds ate feathers, indicating that birds may eat feathers to compensate for the lack of structural components in the feed.

Daily and alternate-day supplementation of urea or biuret to ruminants consuming low-quality forage: III. Effects on ruminal fermentation characteristics in steers.

Five ruminally and duodenally cannulated steers (491 +/- 21 kg BW) were used in an incomplete 5 x 4 Latin square with four 24-d periods to determine the influence of supplemental nonprotein N (NPN) source and supplementation frequency (SF) on the dynamics of ruminal fermentation in steers consuming low-quality grass straw (4% CP). Treatments (TRT) included an unsupplemented control (CON) and a urea or biuret supplement that were placed directly into the rumen at 0700 daily (D) or every other day (2D). The NPN treatments were formulated to provide 90% of the estimated degradable intake protein requirement; therefore, the urea and biuret treatments received the same amount of supplemental N over a 2-d period. Daily TRT were supplemented with CP at 0.04% of BW/d, whereas the 2D TRT were supplemented at 0.08% of BW every other day. Forage was provided at 120% of the previous 5-d average intake in two equal portions at 0715 and 1900. Ruminal fluid was collected 0, 3, 6, 9, 12, and 24 h after supplementation on a day of and a day before supplementation for all TRT. Ruminal NH3-N increased (P < 0.04) with CP supplementation on the day all supplements were provided and on the day on which only daily supplements were provided compared with the CON. However, an NPN source x SF interaction (P = 0.03) on the day all supplements were provided indicated that NH3-N increased at a greater rate for urea as SF decreased compared with biuret. Ruminal NH3-N on the day only daily supplements were provided was greater (P = 0.02) for D compared with 2D. On the day all supplements were provided, D increased (P = 0.05) ruminal indigestible acid detergent fiber passage rate and ruminal fluid volume compared with 2D. These results suggest that urea or biuret can be used effectively as a supplemental N source by steers consuming low-quality forage without adversely affecting ruminal fermentation, even when provided every other day.

Matua bromegrass hay for mares in gestation and lactation.

Matua bromegrass hay (Bromus willdenowii Kunth) is a high quality forage, but its value for mares during gestation and lactation is not well known. Intake, rate of passage, performance, and reproduction by gestating and lactating Quarter Horse mares fed the hay was investigated. In this experiment, 12, 2- to 12-yr-old gravid mares (mean BW = 553 kg, SD = 36) were fed Matua hay (CP = 11.5%) or alfalfa hay (Medicago sativa L.) (CP = 15.4%) for variable days prepartum (mean 59.9 d; SD = 23.5) and for 70 d postpartum. Matua and alfalfa hay were fed as the roughage portion of the diet with a grain supplement. Mares, blocked by age, expected date of foaling, and BW, were assigned randomly within blocks to treatments (six mares per treatment). Forage type did not affect intake, gestation length, birth weight, number of foals, foal weight gain, day of first postpartum ovulation, cycles per conception, or pregnancy rate at 70 d. On d 1, milk from mares fed alfalfa hay contained less (P < 0.03) CP than milk from mares fed Matua hay. Milk CP decreased (P < 0.01) in all mares over time. In a separate experiment, voluntary intake and rate of passage of Matua (CP = 15.5%), alfalfa (CP = 24.9%), and Timothy (Phleum pratense L.) (CP = 4.1%) hays were determined in nine 2-yr-old pregnant mares (mean BW = 447 kg; SD = 21). Diets were 100% forage. Timothy hay did not meet CP requirements for mares. Voluntary intake of alfalfa hay was higher (P < 0.01) than Matua hay. Intake of Timothy hay was lower (P < 0.01) than the mean of alfalfa and Matua hay. Rate of passage offorage was measured by passage of Cr-mordanted fiber. Passage rate and retention time did not differ between Matua and alfalfa hay; however, the retention times of Matua and alfalfa hays were shorter (P < 0.01) than for Timothy hay. Our results indicate that Matua hay is a forage that can be used safely for mares during gestation and early lactation and for their young foals.

Gastrointestinal or simulated in vitro digestion changes dietary fibre properties and their fermentation

This study evaluated the effect of digestion on the chemical and physicochemical characteristics of dietary fibre and on its behaviour during fermentation. Three dietary fibre sources (wheat bran, barley bran and beet fibre) were recovered from ileal cannulated pigs after in vivo digestion and prepared by in vitro enzymatic treatment simulating digestion. Raw substrates and fibre residues were analysed for their chemical and physicochemical properties as well as their potential fermentation by human colonic bacteria. In vitro and in vivo treatments led to insoluble residues, enriched in cell wall polysaccharides, with similar cell wall sugar composition and physicochemical properties. Degradations of cell wall polysaccharides with losses of sugar residues occurred mainly after in vivo digestion, especially for pectins from beet fibre and β-glucans from barley bran. Solubilisation of β-glucans removed highly fermentable substrates for further fermentation. For beet fibre, removal of pectins led to increased hydration properties and faster fermentation of cell-wall polysaccharides. Enzymatic treatment simulated correctly the passage of fibre through the digestive tract, modifying the cell-wall matrix and predisposing the fibre to further fermentation. © 1998 SCI.

Gastrointestinal or simulatedin vitro digestion changes dietary fibre properties and their fermentation

This study evaluated the effect of digestion on the chemical and physicochemical characteristics of dietary fibre and on its behaviour during fermentation. Three dietary fibre sources (wheat bran, barley bran and beet fibre) were recovered from ileal cannulated pigs after in vivo digestion and prepared by in vitro enzymatic treatment simulating digestion. Raw substrates and fibre residues were analysed for their chemical and physicochemical properties as well as their potential fermentation by human colonic bacteria. In vitro and in vivo treatments led to insoluble residues, enriched in cell wall polysaccharides, with similar cell wall sugar composition and physicochemical properties. Degradations of cell wall polysaccharides with losses of sugar residues occurred mainly after in vivo digestion, especially for pectins from beet fibre and β-glucans from barley bran. Solubilisation of β-glucans removed highly fermentable substrates for further fermentation. For beet fibre, removal of pectins led to increased hydration properties and faster fermentation of cell-wall polysaccharides. Enzymatic treatment simulated correctly the passage of fibre through the digestive tract, modifying the cell-wall matrix and predisposing the fibre to further fermentation. © 1998 SCI.

Interactions Among Forages and Nonforage Fiber Sources

Source, amount, and physical characteristics of dietary forage can interact with nonforage fiber sources and influence ruminal and total tract fiber digestion, passage, and performance of dairy cows fed diets containing substantial nonforage fiber in place of forage. Dietary NDF from forage can be reduced to ≤60% and still provide sufficient amounts of effective fiber for FCM production that is similar to or superior to that with high forage diets. Because of small particle size and high specific gravity, increased ruminal rate of passage may be responsible for lower ruminal NDF digestibility of nonforage fiber sources fed at high dietary amounts. As the amount of soybean hulls increased from 50 to 95% of a pelleted mix for dairy cows, passage rate increased by 8%. In five studies, the digestion of soybean hull diets was improved by the addition of coarse forage. Fiber digestibility might have improved because coarse hay increased ruminal retention time of nonforage fiber sources and allowed more complete digestion. Addition of coarsely chopped alfalfa hay to diets based on silage containing 25% soybean hulls increased ruminal mat consistency by 49% and tended to slow the ruminal escape rate of soybean hulls by 16%. When high percentages of nonforage fiber are fed, the amount of dietary forage is necessarily low, and forage particle size should be adequate to stimulate rumination and entrap small feed particles. The amount and particle size of forage in the diet interacts with the substituted nonforage fiber source to determine the net impact on the rate of ruminal digestion and passage of nonforage fiber.

Reduction of cerebellar GABA A responses by interleukin-1 (IL-1) through an indomethacin insensitive mechanism

Recently, a role of IL-1 in the central nervous system has been described, principally a fever-inducing effect in the hypothalamus through a prostaglandin second messenger system. IL-1 has also been shown to potentiate gamma-aminobutyric acid (GABA A) responses in embryonic chick neurones. This study describes the investigation of the effect of IL-1 on GABA A responses within the in vitro rat cerebellar slice, a preparation containing intact neuronal circuitary. Stimulation of the area of passage of parallel fibres produced a pure GABA A inhibition of the spontaneous firing of Purkinje cells. 5 and 10 ng/ml IL-1 produced a reduction in the duration of inhibition 10 min after beginning perfusion of IL-1. This effect reversed within 15 min of washing out the IL-1. 10 ng/ml IL-1 also reduced the effects of exogenously-applied GABA (0.1 mM) with the same time course. In the presence of 1 μM indomethacin, there was no change in the effect of the IL-1. It can therefore be concluded that the reduction in cerebellar GABA A responses by IL-1 is not mediated by the indomethacin-sensitive prostaglandin second messenger system.

Influence of degradability of supplemental protein and time post-partum in early lactation dairy cows. 2. Kinetics of rumen ingesta turnover and whole tract digestibility

Eight lactating dairy cows with rumen cannulae were fed either high or low concentrate totally mixed diets in two blocks of four cows. The forage source was a low quality (9.1% crude protein, 61% neutral detergent (ND) fibre) whole crop oat silage. Degradability of supplemental protein was varied within each block by substituting corn gluten meal, a slowly fermented protein, for canola meal, a rapidly fermented protein. Measurements were made in early lactation (weeks 4 to 13 inclusive) to determine effects of diet concentrate level, degradability of supplemental protein, and time opost-partum on whole tract digestibility, rumen organic matter (OM) and nitrogen (N) pool sizes, and rates of rumen ND fiber passage. Whole tract digestibility of dry matter (DM) and OM was higher for cows fed high concentrate diets, reflecting the higher dietary inclusion of starch, Rumen ND fibre and bacterial OM pool sizes did not differ between dietary concentrate levels. Total non-ammonia N (NAN) pool was higher for cows fed high concentrate diets and this was primarily non-bacterial N, as bacterial N as a proportion of total rumen NAN was higher for cows fed low concentrate diets. Rumen OM and NAN pool sizes were little influenced by dietary protein degradability or time post-partum, although pool sizes of most components tended to increase as time post-partum increased. Rate of rumen ND fibre digestion was lower for low concentrate fed cows. Rate of rumen passage of ND fibre and liquids decreased with increasing time post-partum for low concentrate fed cows.

Studies in fibre digestion and passage rate of liquid and solid in cattle and buffaloes

Rumen liquor characteristics and disappearance rate of dry matter were studied in Kedah-Kelantan cattle and swamp buffaloes fed grass of rice straw-based diet. Cobalt-EDTA and chromium mordented fibres prepared from the faecal material were used to determine the liquid and solid particles movement in both animal species fed with rice straw. Swamp buffaloes showed a more intense rumen fermentation activity than Kedah-Kelantan cattle when both species were fed straw-based diet. The buffaloes also demonstrated faster rates of grass and straw degradation in situ. The fluid outflow rate from the rumen of buffalo (1.06 0.19 1/h) was observed to be slower than that of cattle (1.55 0.01 1/h). No significant differences between cattle and buffaloes were observed in rumen fluid volume and passage rate of small particles from the rumen.

Effect of water-filled bags in the rumen of wethers on ruminal digesta kinetics and total tract nutrient digestibility

Four ruminal cannulated wethers (65 +/- 2.4 kg) were used in a Latin square design experiment to determine the effects of water-filled bags on ruminal liquid and particulate dilution rates. Treatments consisted of ratios of water volume (liters) in bags to pretrial ruminal volume (liters) and were A) 0, B) .22, C) .44, and D) .66. Diet DM, consisting of 75% concentrate and 25% chopped alfalfa hay, was offered once daily at 2.3% of each wether's pretrial live weight. The largest water-filled bag decreased ruminal liquid volume by 68%, increased ruminal liquid dilution rate by 64%, and increased ruminal pool size of non-water soluble concentrate (NWSC) by 137% compared with the control. Ruminal dilution rate of ytterbium-marked NWSC decreased by 37% compared with the control. Ruminal fluid concentrations of NH3 N, pH, and molar ratios of acetate, propionate, butyrate, and isovalerate and plasma urea nitrogen varied over time postfeeding depending on water-filled bag size. Total tract apparent digestibility of DM, OM, ADF, starch, and energy were decreased (P less than .05) with increasing water-filled bag size in the rumen. In this study, water-filled bags acted to increase ruminal liquid dilution rate and decrease ruminal liquid volume and total tract nutrient digestibility but to retard passage of NWSC and hay fiber.

Locomotor behavior changes induced by E-17 striatal transplants in normal rats.

It is well established that embryonic tissue transplantation into an abnormal or lesioned brain can ameliorate some of the accompanying symptomatology. Specifically, transplants placed into kainic acid (KA) or ibotenic acid lesioned striatal rats promote behavioral recovery in various ambulatory measures. In the KA animal model, when the transplant encroached on normal host tissue, the behavioral recovery was diminished. However, little has been done to reveal what effect tissue transplants have on normal host brain. The present study placed E-17 striatal tissue into a normal adult striatum. Digiscan locomotor testing revealed that ten weeks after surgery, the implanted animals demonstrated pervasive nocturnal hyperactivity. Ambulatory, vertical and stereotypic measures were significantly increased when compared to controls. Rats with ten week implants showed lower increases in body gain yet increased food consumption when compared to controls. The transplants survived and contained normal looking AChE positively stained neurons. Evidence for fiber passage through the host-graft interface was also seen. When comparing three and ten week implants, there was a decrease in transplant size in the latter group accompanied by enlarged ventricles giving the brain a lesioned-like appearance. From these results, it is suggested that the placement of E-17 striatal tissue into adult striatum results in lesion-like behavior which may be attributed to the physical disruption of striatal systems.

Comparison of methods to describe the kinetics of digestion and passage of fibre in sheep

AbstractA mathematical model is described which was developed with the objective of analysing and interpreting data from rumen‐emptying studies to estimate rates of digestion (kd) and passage (kp) in sheep offered hay once daily. It assumed that first‐order kinetics applied to digestion in and passage from the rumen within a 24 h feeding cycle. The model predictions of kd and kp were compared with rates of digestion estimated by incubation of the hays in dacron bags and rates of passage determined using chromium‐mordanted hay, in the same experiments. The predictions for rates of passage determined over the period 5–15 h postfeeding were lower than those determined from the chromium‐mordant data and the simulations indicated that the fractional rate of passage during feeding was higher than that recorded in the postfeeding period. This suggests either that more than one fractional rate constant applies within a 24 h period, or that first‐order kinetics do not apply. The estimates for kd were considerably higher than those determined in dacron bags. Evaluation of the ability of the combined dacron bag and mordant techniques to estimate extent of digestion by comparison with in‐vivo digestibility values indicated that the extent of digestion was underestimated. The predictions obtained from the rumen‐emptying data were much closer to the in‐vivo values.

Physical Parameters of Fiber Affecting Passage from the Rumen

Our objective was to review the factors that affect fiber passage from the rumen. Rumen residence time and passage from the rumen are important in control of intake, digestibility, protein metabolism, and protein escape. Physical factors associated with particle size and particle specific gravity affect passage from the rumen. Although particles of 5cm may pass through the reticulo-omasal orifice, most particles leaving the rumen are smaller than 1mm. Polypropylene ribbon cut into 7-cm lengths, introduced into the rumen, markedly reduced intake and were ruminated to fine particle size before being passed. Materials with specific gravity less than 1.0 are ruminated extensively and are passed slowly. As specific gravity of plastic particles increase, rumination of particles is decreased and passage is increased. Particles with specific gravities between 1.17 and 1.42 pass most rapidly. Increasing specific gravities further results in a decline in passage and a further lowering of rumination of particles. Natural hay and fresh forages are hydrated in the rumen, which causes functional specific gravity to increase. Some factors that affect rate of change of functional specific gravity of forages have been investigated. Small particle size, autoclaved rumen fluid, buffer solutions, and specific salts increased the rate of change of functional specific gravity of particles. Understanding of these factors may enable us to make better decisions in managing ruminant productions systems.

UTILIZATION OF POOR QUALITY ROUGHAGES BY SHEEP: EFFECTS OF ALFALFA SUPPLEMENTATION ON RUMINAL PARAMETERS, FIBER DIGESTION AND RATE OF PASSAGE FROM THE RUMEN

Barley straw, bromegrass hay and corncobs were fed with or without alfalfa supplementation to six sheep in a 6 × 6 Latin square design in order to investigate the effects of alfalfa supplementation in the ruminal digestion of untreated poor-quality roughages. Alfalfa supplementation increased ruminal concentrations of valerate and isobutyrate (P &lt; 0.05) for corncobs and of isobutyrate (P &lt; 0.05) for barley straw. In addition, ruminal ammonia-N levels were increased by supplementation (P &lt; 0.05) for all diets. This improvement in the rumen environment was reflected by increase (P &lt; 0.05) in sacco rates of fiber digestion which were 4.63 and 5.85%/h, 4.73 and 6.18%/h, 3.78 and4.57%/h, without and with alfalfa, respectively, for barley straw, bromegrass hay and corncobs. For corncob diets, rates of passage of indigestible material were increased by supplementation from 1.87%/h to 3.06%/h (P &lt; 0.05). These results explain some of the associative effects on digestion that have been noted between poor and good quality roughages. Key words: Roughage quality, sheep, digestion kinetics, fiber passage, rumen parameters, supplementation

Effect of Forage: Concentrate on Kinetics of Forage Fiber Digestion In Vivo

With five rumen-fistulated Holstein steers in a Latin square design, we determined the effect of dietary concentrate (0, 20, 40, 60, or 80% cracked corn) on kinetic characteristics influencing forage fiber digestion in vivo. Rate and potential extent of neutral detergent fiber degradation were determined for fescue hay in situ by nylon bag technique. Rate of fiber passage from the rumen was measured by fecal excretion of chromium-mordanted fescue cell walls. Apparent extent of forage fiber digestion was predicted by a model in which fiber disappearance from the rumen is conceptualized as the sum of two competing first-order processes, digestion and passage, modified further by a discrete lag time during which fiber passes from the rumen before digestion commences.Stepwise multiple regression analysis revealed that potential extent of fiber degradation in situ was the primary determinant of depression of fiber digestibility as dietary concentrate increased. Rate of digestion, rate of passage, and lag effects collectively accounted for a small portion of the depression of fiber digestibility.

Digesta Passage Measured by Markers in Dairy Cows Fed Two Ratios of Corn Silage:Grain with 0 or 1.2% Sodium Bicarbonate

Four multiparous Holstein cows in midlactation fitted with rumen cannulae were in a 4×4 Latin square experiment to examine effects of two ratios of corn silage:grain (50:50 or 75:25) and sodium bicarbonate (0 or 1.2% of ration dry matter) on rate of passage of digesta. Marker techniques and mathematical equations were compared. Markers for liquid phase were polyethylene glycol and cobaltethylendiaminetetraacetic acid and for particulate phase were lanthanum, samarium, cerium, and chromium-mordanted fiber. A single compartment model was used to measure rate of passage of liquid from concentration of the two markers in ruminal fluid samples. Two two-compartment mathematical models were used to calculate rates of passage of liquid, grain, and fiber from fecal marker concentration. Ruminal liquid volume, rate of flow, and fractional rate of passage were not affected by sodium bicarbonate but increased with greater silage feeding. Ruminal grain and fiber passage were increased when more corn silage was fed. Effects of sodium bicarbonate on ruminal grain and fiber passage were variable, although fiber passage tended to be slowed. Overall, liquid passage exceeded grain passage, which exceeded fiber passage from the rumen. In the total tract, retention time of liquid, grain, and fiber was less when diets contained 75% corn silage. The effect of sodium bicarbonate on retention time of liquid, grain, and fiber in the total tract was variable. Markers and mathematical calculations caused differences in estimates of rate of passage and interpretation of results.

Asbestos-related mesothelioma: epidemiological evidence for asbestos as a promoter.

A series of 144 cases of mesothelioma among asbestos workers indicated important divergences from the epidemiological pattern shown to exist for asbestos-related lung cancer. Consideration of exposure duration and intensity and the latent period between first exposure and death suggests that asbestos does not act as a complete carcinogen, but as a promoter. A threshold seems probable for both duration and intensity of exposure in the induction of mesothelioma. This threshold may, in part, be related to the passage of fibers from the lungs to the pleura or peritoneum, and would, in any case, be masked in lung cancer by the retention of asbestos in the lungs. Reported cases of mesothelioma in immediate family members indicate the existence of an additional factor in mesothelioma induction, acting earlier in life than the first asbestos exposure.

Monitoring Water Filters for Asbestos Removal

Water filtration processes can reduce the asbestos fiber count in drinking water by 90 to 99.9 percent, or more. Effective fiber removal requires very close control of the treatment process. Monitoring of filtered water turbidity can indicate the efficacy of treatment, even though the asbestos fiber concentration is too low to register as turbidity. Turbidity monitoring works because when water is properly prepared for filtration, passage of asbestos fibers through the filter is indicated by the passage of floc, as shown by higher turbidity. Filtered water turbidity should be 0.10 ntu or below for best fiber removal. Continuous monitoring of each filter module at a treatment plant is recommended. These findings are based on studies at Duluth, Two Harbors, and Silver Bay on Lake Superior; Seattle’s Tolt reservoir, and on data obtained from the San Francisco Bay area.

Recovery of ingested asbestos fibers from the gastrointestinal lymph in rats

Using the transmission electron microscope, asbestos fibers have been assessed in lymph fluid collected from the thoracic lymph duct in five groups of rats previously exposed to asbestos fibers (by ingestion). Ten rats were gavaged a single dose weighing approximately 20 mg. Five were given pure UICC chrysotile A while another group of five had pure UICC crocidolite. All the rats of the chrysotile group were positive animals with recovery rate values ranging from 6.9 × 10 −7 to 3 × 10 −5 (90% of the fibers being recovered during the first 16 hr following the gavage). The crocidolite group had only three positive animals and lower recovery rate values of 5.7 × 10 −8 to 5.6 × 10 −7. A third group was fed a synthetic diet containing 1%, by weight, chrysotile with a majority of short fibers (90% below 4 μm). Of the 15 rats comprising this group, 13 were positive with maximum daily recovery rates ranging from 2.1 × 10 −7 to 2.1 × 10 −6. A group of eight rats fed the same kind of diet but containing a higher proportion of long fibers, showed only four positive animals, however, they had higher daily recovery rates ranging from 1.9 × 10 −5 to 2.1 × 10 −4. No fibers were encountered in the samples of the two control rats. This study demonstrates the passage of chrysotile and crocidolite fibers across the gastrointestinal wall, with the passage rate being higher for long fibers than short ones.

Altered retinotectal topography in hamsters with neonatal tectal slits

Alterations in normal retinotectal topography by mechanical disruption of fiber passage during development was studied in Syrian hamsters using both neuroanatomical and electrophysiological techniques. The mechanical block to fiber passage was created with a medial to lateral slit across the superior colliculus on the day of birth. At maturity, topographically aberrant projections were found in areas of residual scar tissue. These aberrant projections were synaptically functional, producing neurons with mutiple, spatially separated visual receptive fields. No evidence was found for an orderly compression of the retinotopic map in the tectum consequent to the transitory blockage of fiber passage.