Fistula Samples Research Articles

Changes in chemical composition and in vitro digestibility of oesophageal fistula and hand plucked forage samples due to drying method and stage of maturity

The preparation method used for forage samples after collection is important when obtaining their nutritive value with acceptable accuracy and precision. This study was conducted to evaluate the effect of oven drying (40°C) or freeze drying on the nutritional components of forage samples collected: (1) from a shrubland, at monthly intervals through the year; and (2) from woody species at various stages of maturity. Collection occurred both by hand plucking and via oesophageally fistulated goats. The woody species tested were kermes oak ( Quercus coccifera L.), oriental hornbeam ( Carpinus orientalis Mill.), manna ash ( Fraxinus ornus L.), oak species ( Quercus pubescens Wild.) and rock-rose ( Cistus incanus Rchb.). Oven-dried fistula samples produced artificially increased levels of neutral detergent fibre and lignin, while the in vitro organic matter digestibility was underestimated in comparison with freeze-dried samples during all grazing periods. A similar pattern was observed for the hand-clipped samples during the rapid growing season, when the moisture content was high while during the remaining periods of the year, no significant differences were detected. For nutritional studies, when samples contain high proportions of moisture, the only acceptable method is freeze drying.

Performance of Manchega ewes grazing cereal stubbles and cultivated pastures

Sparsity and seasonality of most Mediterranean grazing land resources requires diversification in order to complete full cycles of pregnancy and lactation, including grazing winter cereal stubbles and stockpiled sown pastures. Early November was the mean lambing date. Over the gestation period the ewes selected a much better quality diet than the resources offered (oesophageal fistula samples had 63.3% digestible dry matter (DDM) and 12.8% crude protein (CP). Nevertheless, low values of dry matter (DM) intake (1100 g DM per ewe per day) made it advisable to add supplement late in pregnancy. Higher levels of DM intake (1740 g DM per ewe per day) with a better quality diet (78.3% DDM and 20.0% CP) were obtained on the stockpiled pastures. Lactating ewes reacted to no more than 0.5 kg concentrate per ewe per day mainly by decreasing liveweight loss. Little differences were found from the effects of ewes' supplementation on lambs' liveweight gain (average 201 g d −1) or ewes' milk yields (average 694 ml d −1).

Remote control collection of oesophageal fistula samples in goats

A lightweight radio controlled valve was developed for the collection of forage samples from oesophageal fistulated goats. Number and size of samples can be varied and collected throughout the day without disturbing the animal's normal feeding behaviour. In a preliminary test, 74 extrusa samples were collected. Seventeen were considered failures due to blockage of the valve and disconnection of the power supply to the valve motor. Careful timing of the opening and closing of the valve and proper protection of the electric wires seems to have solved these problems satisfactorily.

Voluntary intake and quality of diet selected by cattle grazing bana grass, kikuyu and forage sorghum

Bana grass (Pennisetum purpureum x P. amerieanum) was compared with kikuyu (P. clandestinum) and forage sorghum (Sorghum bicolor) with respect to quality of samples ;elected by four oesophageally fistulated steers. Hand-cut samples of the three forages were also compared with fistula samples for certain quality parameters. No significant difference (P ≥ 0,05) was found between IVDOM and N content of hand-cut and fistula samples, but ADF and NDF values differed significantly (P ≤0,01). Grazing significantly (P ≤0,05) reduced the leaf: stem ratio of the pastures. Changes in this ratio were, however, not consistent among the different species over different periods. Kikuyu contained more N throughout the growing season than bana grass or sorghum (P ≤0,01), while the IVDOM of sorghum was less (P ≤0,01) than that of bana grass and kikuyu. Seasonal trends were significant on occasions. Kikuyu contained less cell wall (NDF) (P ≤0,05) than bana grass and sorghum but the disappearance of NDF from nylon bags only differed significantly between kikuyu and sorghum. Organic matter intake (faeces voided measured by faecal bags) was consistently in the order of bana grass > sorghum > kikuyu, with a significant (P ≤0,05) difference between bana grass and kikuyu. It was concluded that the general assumption in the literature that hybrid Pennisetum species based on Napier are soft and palatable, may be true for bana grass as well

Elevated Plasma Histamine in Chronic Uremia Effects of Ketotifen on Pruritus

A role for histamine in the pathogenesis of uremic pruritus was investigated in maintenance hemodialysis patients. Venous plasma histamine levels, as determined by radioenzymatic assay, were significantly higher (p less than 0.05) in hemodialysis patients with pruritus (368 +/- 103 pg/ml [mean +/- SEM], n = 6) than in those without pruritus (146 +/- 22 pg/ml, n = 5) and in normal controls (142 +/- 16, n = 5). Arteriovenous fistula histamine levels (202 +/- 52 pg/ml, n = 6) were significantly lower (p less than 0.05) than simultaneously drawn venous samples. Markedly elevated histamine-degrading enzyme (histaminase) activities were found in both hemodialysis patients with (2.95 +/- 0.18 pg histamine degraded/minute) and without (2.44 +/- 0.28) pruritus, but was undetectable in normal controls. Histaminase activities did not significantly differ in simultaneously drawn venous and fistula samples. With hemodialysis, histaminase activities fell significantly (p less than 0.01), whereas plasma histamine did not change. We further examined the effects of ketotifen, a putative mast cell stabilizer, on severe uremic pruritus. Five of five patients had significant (p less than 0.01) reductions in pruritus, as judged on a six-point pruritus index, after 8 weeks of drug (x = 2.3), as compared to conventional therapy (x = 5.9). Despite these improvements, no significant differences were noted in pre- versus post-drug plasma histamine levels, histaminase activities, or the histamine content per gram of skin biopsy specimen. These data support prior hypotheses that mast cell activation contributes to the pruritus of uremia.

The effect of veld condition on the quality of diet selected by cattle grazing the Natal Sour Sandveld

The quality of diet selected by steers fistulated at the oesophagous was related to veld condition in a simulated rotational grazing system on the Natal Sour Sandveld. Six camps, ranging in veld condition score from 8,5 to 53%, were grazed simultaneously for a two‐week period in spring, summer, autumn and winter. Fistula samples were collected on the first, middle and last day of a period of occupation in a camp. Samples were analysed in terms of crude protein (CP), in vitro digestibility (IVD) and plant‐part (% leaf, % stem and % dead material) composition. Dietary quality in terms of CP, IVD and plant‐part composition was not related to veld condition but was dependent largely (P≤0,01) upon season and to a lesser extent upon period of occupation in a camp. It was concluded that in sourveld areas, where dietary quality may be limiting, the veld condition score may be a poor index of potential animal production.

Comparison of Microscopic and Pinitol Techniques in Determining Legume Composition of Steer Diets1

AbstractKnowledge of botanical and chemical composition of herbage consumed by grazing livestock is essential in understanding animal performance and improving pasture and animal management. Esophageal fistula samples are considered to best represent cattle (Bos spp.) diets, but current microscopic methods used to determine botanical composition are time consuming, expensive, and may be subject to large operator error. Pinitol (1‐D‐3‐O‐methyl‐chiro‐inositol) has been found unique to the leguminosae family and accurate in determining alfalfa (Medicago sativa L.) percentage in greenhousegrown alfalfa‐tall fescue (Festuca arundinacea Schreb.) mixtures (R2 = 0.99). Its utility in estimating the legume composition of esophageally collected grass‐legume samples was compared to that of two widely used microscopic techniques. No significant differences were found between microscopic methods in pasture or hay aftermath of any treatments or dates. Sensitivity analysis showed no differences in the two methods related to their ability to detect dietary legume concentration changes in esophageal samples. Pinitol estimates of legume content were less (P<0.05) than those from microscopic estimates taken from orchardgrass (Dactylis glomerata L.) + legume [red clover (Trifolium pratense L..), birdsfoot trefoil (Lotus sp.), or alfalfa] pasture and hay aftermath, but not from nearly pure orchardgrass. The three methods provided similar estimates late in the grazing season when all values were low. With few exceptions the pinitol method underestimated legume composition of esophageal samples. In a separate experiment, the pinitol content of alfalfa, red clover, and birdsfoot trefoil extrusa after mastication and salivation was lower than that of unfed samples, suggesting that leaching may have been partially responsible for low estimates of legume composition by the pinitol method

Grazing System Influences on Cattle Performance on Mountain Range

A 5-year study was conducted to evaluate the influences of rest-rotation, deferred-rotation, and season-long grazing systems on cattle diet botanical composition and quality and weight gains on mountain rangeland in northeastern Oregon. The grazing season in each year lasted from 20 June to 10 October. Esophageally fistulated animals were used to evaluate diet quality and botanical composition. All study pastures included forest, grassland, and meadow vegetation types. Each pasture had a north and southfacing slope divided by a riparian zone and creek. The grazing pressure for each system was similar. Grazing intensity was the same as National Forest Allotments in the area. There were no differences (P>.05) in weight gains among the 3 systems when data were pooled across years. Crude protein, in vitro organic matter digestibility, and acid detergent fiber percentages in fistula samples did not differ (P>.05) among systems for any year of study or for data pooled across years. Mid-season movements of cattle under the rest-rotation system had little influence on their diet and performance compared with cattle under the season-long system. Key forages in cattle diets were Idaho fescue (Festuca idahoensis), bluebunch wheatgrass (Agropyron spicatum), and common snowberry (Symphoricarpos albus). Cattle diet botanical composition under the 3 grazing systems did not differ (P>.05).

Fistula Sample Numbers Required to Determine Cattle Diets on Forest and Grassland Ranges

Fistula Sample Numbers Required to Determine Cattle Diets on Forest and Grassland Ranges

Correcting for Salivary Contamination of Esophageal Fistula Samples

Correcting for Salivary Contamination of Esophageal Fistula Samples

Relationships between Performance, Intake, Diet Nutritive Quality and Fecal Nutritive Quality of Cattle on Mountain Range

Correlations were developed between average daily gain (ADC), forage organic matter intake (INT), fiitula sample ln vitro organic matter digestibility (DID), futula sample nitrogen (DN), fecal sample in vitro digestibility (FID), and fecal sample nitrogen (FN) of cattle on forest and grassland range in northeastern Oregon. FN and FID were more closely associated with ADG and INT than DN or DID. Linear regression equations were developed between fistula and fecal samples for both N (rZ= S3)and ID (rj= .71). The inclusion of FN as an independent variable with FID improved the equation for predicting fistula sample ID (Rz = .83). Forage intake could not be well predicted from either FN or FID in either simple or multiple regression equations. The closer relationship between fecal sample nutritive quality and ADG compared to fistula sample nutritive quality and ADG is attributed to greater sampling precision for fecal nutritive quality. Fecal N and ID appear to be closely associate with DN and DID when grasses comprise most of the ruminant diet but this relationship may not hold when the diet is dominated by forbs and shrubs. Nutritive evaluation of feces shows potential for monitoring trends in ruminant diet quality and performance but much more research isneeded before these procedures can be applied. Trends in ruminant fecal nutritive quality are associated to varying degrees with trends in diet quality (Raymond 1948, Fels et al. 1959, Jarrige 1962, Arman et al. 1975, Hinnant 1979, Holloway et al. 1981) and animal performance (Erasmus et al. 1978, Gates and Hudson 198 1). Three studies have shown a close relationship between percentage nitrogen in the diet and percentage nitrogen in the feces of ruminant animals (Raymond 1948, Fels et al. 1959, J.L. Holechek and D. Arthun are assistant professor and graduate assistant, Department of Animal and Range Science, New Mexico State University, Las Cruces. N.M. 88003. Martin Vavra is professor of range nutrition. Oregon State University, Eastern Oregon Agricultural Research Center, Union. 97883. This report is Journal Article 822, Agricultural Experiment Station, New Mexico State University, Las Cruces 88003. JOURNAL OF RANGE MANAGEMENT Xi(6). November 1962 Hinnant 1979). A recent study indicates diet and fecal in vitro digestibility are associated (Holloway et al. 1981). Erasmus et al. (1978), in South Africa, found that trends in wild ungulate body condition were closely associated with trends in fecal nutritive quality. Gates and Hudson (198 1) accounted for 85% of the variation in daily gains of elk with fecal N concentration. Based on these studies it might be possible to monitor changes in ruminant condition and diet using fecal analysis. The study reported, herein, examined the relationships between cattle performance, intake, diet nutritive quality, and fecal nutritive quality on mountain range in northeastern Oregon during 3 grazing seasons. In vitro organic matter digestibility and nitrogen were the nutritive characteristics receiving evaluation.

Prediction of Forage Quality Using Near Infrared Reflectance Spectroscopy on Esophageal Fistula Samples from Cattle on Mountain Range

Prediction of Forage Quality Using Near Infrared Reflectance Spectroscopy on Esophageal Fistula Samples from Cattle on Mountain Range

Botanical Composition Determination of Range Herbivore Diets: A Review

Botanical Composition Determination of Range Herbivore Diets: A Review

Cattle Diets in the Blue Mountains of Oregon II. Forests

Cattle Diets in the Blue Mountains of Oregon II. Forests

The Microhistological Technique: Testing Two Central Assumptions in South-Central New Mexico

Analysis of the botanical content of diets of livestock, big game, small mammals, and insects has become common in research. The better known dietary analyses utilize either stomach, fecal or esophageal fistula samples. The respective advantages and disadvantages of these procedures have been recognized, and the use of a particular procedure is dictated by the type of study, subject animal, available facilities, time, manpower, and information desired. Methods for quantifying the diet sample obtained by an analytical procedure have been generalized as visual appraisal, manual separation, microhistological techniques, and microscope point techniques (I’heurer et al. 1976). Of these general categories, visual appraisal and manual separation are limited by the ability of the researcher to quantify individual species in the sample diet. Hence, these methods may contain large inherent personal errors. The microscope point techniques require statistical regression procedures, determination of species weight/volume relationships, and overestimation correction tactors. The microhistological techniques have become the most favored method. Sparks and Malechek (1968) have outlined the basic procedure for this method. However, its accuracy in determining dry-weight composition of masticated forage samples was not examined. The objective of this study was to examine two central assumptions of the microhistological technique and determine if these assumptions were satisfied when determining dry-weight composition of masticated forage samples from blue grama (Bouteloua grucilis) foothill mngeland. These assumptions were that percent frequency can be used to estimate particle density and the percent of identifiable material is constant for each species. Methods Samples were collected from esophageal-fistulated steers grazing native shortgrass rangeland in south-central New Mexico. The study area was located on the Fort Stanton Experimental Ranch. The blue grama-dominated rangeland has been described by Allison et al. ( 1977). Dietary sampling was conducted during 1975 and 1976. Three periods representing three different plant growth stages+arly summer, late summer, and mid winter-were selected for study. Handling and slide preparation of sample material as well as calculations for frequency, particle density, relative density, and percent dry-weight followed the procedure outlined by Sparks and Malechek (1968). Five slides were prepared for each sample period, and 20 systematically located fields were sampled for particle frequency and density on each slide to give 100 fields for each period. Reference material for all species present was collected during late summer. Reference slides, drawings, and photographs were utilized in identifying species within sample diets. When a particle observed in a field could not be identified, the slide was moved so that identification was improved by observing the entire particle.

EVALUATION OF A DEHYDROGENASE ASSAY BASED ON TETRAZOLIUM REDUCTION FOR RAPID IN VITRO ESTIMATION OF FERMENTATION ACTIVITY IN RUMEN CONTENTS

Rumen contents obtained from fistulated steers fed brome–alfalfa hay was used to evaluate a dehydrogenase assay based on the reduction of 2,3,5-triphenyltetrazolium chloride (TTC) to triphenylformazan (TPF) for rapid in vitro estimation of fermentation activity. Maximum absorbance of TPF occurred at 485 nm over the pH range 3–10. TPF formed from TTC was stable to atmospheric O2. Absorbance decreased if TPF was exposed to light. In the presence of excess TTC, production of TPF in strained rumen fluid (SRF) at 39 °C was linear with elapsed incubation times up to at least 5 min. Dehydrogenase activity was abolished in the presence of air. It was significantly increased if the CO2 gas phase above SRF was replaced with N2 or H2, owing, at least in part, to an increase in the pH of the fermentation. The dehydrogenase activity of SRF was maximal at pH 7.8–8.0. Fractionation of SRF by differential centrifugation showed that about 50% of the dehydrogenase activity was associated with a protozoal fraction sedimenting at 188 × g, and 42% with a bacterial fraction sedimenting at 1,475 × g. Neither the cell-free supernatant obtained by centrifuging SRF at 21,500 × g, nor boiled SRF, nor the hay fed to the animals showed dehydrogenase activity. Whole rumen contents (WRC) showed a mean dehydrogenase activity that was 58% higher than that of SRF. The dehydrogenase activity of SRF was increased in the presence of substrates representing major plant carbohydrates, the greatest stimulatory effect being shown by ground brome–alfalfa hay. When rumen contents were sampled at the same time by stomach tube and through the fistula, the mean dehydrogenase activity of SRF prepared from the stomach tube samples was 137% higher than that of SRF prepared from the fistula samples. In an animal fed at 12-h intervals, the dehydrogenase activity of SRF rose within 2 h after feeding, declined for the next 6 h, and showed a second peak at 9 h. Activity then declined to the pre-feeding level. The dehydrogenase activity of WRC showed a similar pattern but the peaks of activity were less pronounced. It was concluded that dehydrogenase activity based on TTC reduction provides a simple and rapid means of estimating the fermentation activity of rumen contents which may reflect the availability of energy substrates to the microbiota.

Factors affecting the digestion of oesophageal fistula samples and hay samples in nylon bags in the rumen of cattle

SUMMARYFactors affecting the nylon-bag technique, for examination of digestion in the rumen of extrusa and hay samples of low nutritional value, were studied. Effects of: the method of placement of bags in the rumen; saliva in extrusa; drying and milling techniques; a second-stage digestion with acid-pepsin solution; sample size; and losses of particulate matter through bag cloth were studied. Digestion of dry matter (d.m.) and cell walls after 12, 24, 48, 72 and 168 h in the rumen were used to indicate treatment effects.Attaching bags with nylon cord to a weight was a better method than enclosing them in perforated jars in the rumen which restricted digestion. Drying technique had little effect on digestion, although frozen extrusa was digested more than oven-dried feed, especially in samples of Heteropogon contortus. Chewing of forage was sufficient to obtain maximum rates of digestion. Milling extrusa through 1 or 2 mm screens did not increase digestion. An extra period of digestion in acid-pepsin solution increased digestion of feed samples more than that of extrusa, but the effects were small. It reduced between-bag variation slightly, but did not alter the significance of differences between treatments. The effect of sample size on digestion was small. Sample weight (3, 6 and 9 g) was kept proportional (42 mg/cm2) to bag cloth area.Digestion of d.m. after 24 h reflected digestion of cell walls. Digestion of cell walls was faster in grasses than in legumes. The higher digestibility of legumes was due to solubilization within 24 h of the greater amounts of cell contents found in legumes. Cell contents were only partially solubilized, and up to 10 g per 100 g original d.m. were not removed. Losses of particulate matter averaged 4·6% (range 0·5–10·6%). Losses were high when samples were finely milled (1 mm screen) but varied between species. Pore aperture of cloth was 25 μm. Methods for determining loss and correction of digestion data for such losses are given.

A Comparison of Esophageal Fistula and Fecal Material to Determine Steer Diets

Highlight: Cattle diets were determined by esophageal fistula and fecal material collection procedures from yearling cattle grazing shortgrass range in northeastern Colorado. Diets were quantified by microhistological procedures from samples collected in June, July, August, and December of 1969; and June, July, and August of 1970. Total grasses occurred significantly less in esophageal samples, while total forbs were significantly lower in fecal samples. Individual grass species did not appear to follow a set pattern of variation from esophageal to fecal sampling; some were greater in fecal samples while others were greater in fistula samples. Forbs occurred at greater percentages in fistula samples, with the exception of burning bush (Kochia scopuriu) in 1969. Correlation and regression analysis revealed little relationship in botanical composition determined on fecal and esophageal samples. However, an importance value ranking revealed esophageal and fecal samples were similar when individual species were ranked from the most common to the least common in the diet.

Estimation by calcium analysis of the proportion of grass in oesophageal fistula samples from cattle grazing grass-stylo pastures

Variation in calcium (Ca) concentration in tropical grasses and Stylosanthes species growing in paddocks with and without superphosphate fertilizer was examined at six intervals over one year on whole plant tops and on hand-plucked samples. Variation in Ca concentration between plant parts was also measured on one sampling date. Extrusa samples obtained from cattle fitted with oesophageal fistulae in two grazing experiments were used to examine the relation between the Ca concentration and the botanical composition determined by the microscope-hit method. The concentration of Ca was 2.2 to 5.2 times greater in legumes than in grasses. While it decreased in legumes with increasing plant maturity, it remained relatively constant in the grasses, especially in those receiving fertilizer. Calcium concentration did not vary greatly between plant parts in the grasses, but the legume stems had lower (0.77 per cent Ca) concentrations than legume leaves (1.58 per cent Ca). The relationships found in the two grazing experiments did not differ, and the resulting combined equation describing it was : y = 128.4 - 82.0x (n = 40; r2 = 0.822; S y . x = 12.6) where y = per cent grass and x = per cent Ca.

Mineral Composition of Rumen Fistula Samples Compared to Diet

Forage sampling using fistulated grazing animals is a generally accepted technique to measure dietary forage quality and botanical composition, but is it a satisfactory technique to evaluate dietary mineral intake? Using a variety of diets which were fed to rumen-fistulated steers, the fistula samples had relatively larger concentrations of ash, Si, Na, P, Zn, and Co (PC 0.05) than did diet samples. Small decreases in the Mg and Ca concentrations of the fistula sample, as well as the small increases in N, K, Mn, Fe, and Mo values, were not generally different from diet concentrations. Regression equations predicting diet-mineral concentrations of all diets, given the concentration in the fistula sample, were accompanied by errors of 8 to 37% of the true value. Smaller errors can be expected when similar diets like alfalfa hay are used throughout a given study.