Rumen Liquor Samples Research Articles

Desenvolvimento de populações de protozoários ciliados no rumen de ovinos (Ovis aries L.) criados em Itapetininga, São Paulo

Using a oesophageal tube, rumen liquor samples were collected from five Corriedale, five Ideal and five Suffolk sheep, male and female. The results showed a normal population in animals from 2 to 11 months old, but stabilization began only at the age of 8 months, with the following average counts per ml and relative percentages: Entodinium sp: 146.012.8 (76.16%); Diplodinium sp: 30.429.3 (15.7%); Epidinium sp: 8.147.9 (4.25%); Isotricha sp: 1.409.6 (0.73%); Dasytricha sp: 5.729.9 (2.99%); and total of ciliates: 191.729.5. The pH was 6.90 at stabilization.

Measurement of volatile fatty acid production rates in sheep given roughage

Measurement of the irreversible loss rate (ILR) of acetate, propionate and butyrate by radioisotope dilution of the respective tracers in sheep offered chopped dried grass from continuous belt type feeders gave 'plateau samples', the specific radioactivity of which had unacceptably high variance (coefficient of variation [cv] of the five or six samples taken from any one animal over the last four hours of 10 hours infusion ranged from 16 to 57 per cent). In an experiment which attempted to identify the source of this variability the distribution of the liquid phase marker 51Cr EDTA into different areas of the rumen was examined during its administration either in liquid form or impregnated on paper. The paper provided better mixing but incurred considerable spillage problems which would be unacceptable where calculations of ILR were required. Radiographic observations were made to examine the mixing of radio-opaque liquid and solid phase markers in the rumen. A better mixing of both was achieved with intermittent than continuous feeding. When 1-14C- and 2-14C-labelled acetate were each infused into the rumen of four sheep given two levels of chopped dried grass by means of hourly feeders, samples of rumen liquor gave much lower variability of the mean plateau specific radioactivity values than was obtained in experiment 1 (cv less than 15 per cent in all but one sheep). The ILRs of acetate and the transfer quotients of carbon from acetate to butyrate obtained using 1-14C- and 2-14C-labelled acetate were similar.(ABSTRACT TRUNCATED AT 250 WORDS)

The presence of oxygen in rumen liquor and its effects on methanogenesis

In situ measurement of O2 in the rumen liquor of cows, sheep and goats using a membrane‐covered O2 electrode revealed the presence of up to 1630 nmol/l O2; O2 became undetectable immediately after feeding of animals. The effects of O2 on H2 production and methanogenesis in samples of rumen liquor were investigated using a mass spectrometer fitted with a membrane inlet system. Methanogenesis was totally and irreversibly inhibited after short term exposure (about 10 min) to 5 KPa (0·05 atm) O2; H2 production was unaffected. Glucose additions produced rapid transient increases in H2 levels and increased O2 uptake.

The effect of dietary N onin vitrolipolysis and fatty acid hydrogenation in rumen digesta from sheep fed diets high in starch

SUMMARYFive Romney wethers, fitted with rumen fistulae, were each fed five pelleted diets high in starch (30–50%) containing 0·72, 1·22, 1·72, 2·47 and 3·72% N respectively. Samples of rumen liquor were incubated with glycerol-tri-[1-14C]oleate or with [1-14C]- linoleic acid. The rates of lipolysis or hydrogenation of these substrates were measured. In addition rumen contents of the sheep when fed the 1·22% N diet were incubated with radioactive substrates plus 0, 100 and 200 mg finely ground casein.It was found that there was an approximately linear increase in the rate of lipolysis between 0·7 and 2·5% N. The rate of hydrogenation did not increase below l·2% N and tended to decrease above 2·5% N. The potential for hydrogenation of unesterified linoleic acid was calculated to be 4–6 times greater with all diets except that containing 1·2% N. This may be one explanation for the elevated concentration of the rumen unsaturated fatty acids in sheep fed diets containingca.1–1·5% N.It was also established that the addition of finely ground casein to the incubate was without effect.It was concluded that microbial composition is important in regulating the relative rates of lipolysis and hydrogenation which determined the amount of unsaturated dietary fatty acid present in the rumen.

Behavior of the trace elements copper, zinc and manganese in bovine rumen. 1. Trace element content of different fractions of rumen fluid and the effect of copper sulfate administration

Two adult, rumen-fistulated steers were fed, over four consecutive 3-week periods, Cu-deficient and normal hays with and without copper sulphate supplementation. Their rumen liquor levels of copper, zinc and manganese were determined correspondingly. The rumen liquor samples were split into 3 fractions by way of centrifugation, sodium dodecyl sulphate treatment of the sediment and filtration. The fractionation of the rumen liquor showed copper to be contained mainly in the water-soluble supernatant (68%), whilst zinc and manganese are more strongly linked to the microbial fraction (57 and 46%, resp.). The plant residue did not average but 9, 24 and 22% of copper, zinc and manganese, respectively. Copper sulphate supplementation to normal hay resulted in a significantly increased copper content in the supernatant and in the microbial fraction. At the same time, the zinc and manganese content values in the microbial fraction were found increased. However, the same copper sulphate supplementation to Cu-deficient hay was found to reduce highly significantly the copper level in the microbial fraction. It is supposed that the excessively high molybdenum content of this hay (2.5 ng/kg) has prevented any effect of the copper sulphate supplementation. The positive effects of copper sulphate supplementation on the zinc and manganese levels in the bacterial fraction were maintained even when feeding Cu-deficient hay rich in Mo.

The nutrition of ruminants grazing native and improved pastures. I. Seasonal variation in the diet selected by grazing sheep and cattle

The chemical composition of the forage on offer on a native pasture dominated by Poa sieberana and Themeda australis, on a similar native pasture dressed with superphosphate and oversown with white clover, and on two Phalaris aquatica (formerly tuberosa)–Trifolium repens pastures dressed with superphosphate and grazed at different stocking rates during summer, was determined at monthly intervals during 1974 and 1975. Samples were also plucked to simulate grazing in 1975, and extrusa were collected from oesophageally fistulated cattle in both years and from fistulated sheep in 1975. Digestibility and nitrogen content of the diet were determined, and in 1974 the extrusa were manually separated into green and senescent fractions. Samples of rumen liquor were also collected through rumen fistulae, and analysed for ammonia, and total and individual volatile fatty acids. The application of superphosphate and white clover, and the replacement of native grasses with Phalaris aquatica, both induced large increases in nutritive value measured in terms of digestibility, protein, macro- and micro-elements in the forage on offer and in the diet selected. Changes in the composition of the forage on offer were attributable to an increase in green material, and to the greater nutritive value of both green and senescent fractions as the extent of pasture improvement increased. Digestibility, nitrogen and mineral content of the diet selected by cattle and sheep increased with pasture improvement, the nutritive value of the diet selected by sheep being greater on all pastures although the difference was greatest on native pasture. The increase in nutritive value of the diet selected by cattle on improved pasture was associated with an increase in the green component of the diet and in the nutritive value of the green material selected.

The effects of selenium on the metabolism of methionine in sheep

Two groups of sheep fed a diet of hay known to produce nutritional muscular dystrophy, one group of which received selenium supplementation, were used to study the effects of selenium on the metabolism of administered L-(35S) methionine by rumen microflora. Rumen bacterial proteins of the Se supplemented sheep contained significantly higher levels of radiosulfur than the bacterial protein of the non-supplemented sheep. Of hte L-(35S) methionine present in the rumen liquor samples from Se-supplemented sheep 2 h after administration, 13.3% of the amino acid, which was measured as methionine sulfone, was found in the microbial proteins. A large proportion of the administered labeled methionine was resynthesized as cyst(e)ine which may account in part for that determined as cysteic acid in rumen bacterial and plasma proteins. The observed low levels of radiosulfur found in rumen microflora from selenium deficient wethers, indicates that the presence of selenium profoundly affects the rate of methionine metabolism and the distribution of methionine in rumen bacterial and protozoal proteins. In another experiment, the effect of selenium on the metabolism of L-(Me-3H) methionine was studied. The selenium status of the sheep had no significant effect (P greater than 0.05) on the distribution of 35S radioactivity in the blood plasma and tissues.

Metabolism of Liquid Whey Fed to Sheep

Digestion was studied with three groups of four sheep each fed alfalfa hay. Treatments were whey only, whey plus water, and water only. Digestibilities of dry matter for the three rations were 71.3, 69.7, and 62.9%. Digestibilities of whey solids calculated by difference was 86.9% for whey only and 81.6% for whey plus water. Twelve sheep were in three trials to determine the intake of whey, water, and hay consumption. They were assigned to whey only, whey plus water, and water only. Hay, whey, and water consumption was 1.89, 8.73, and 0; 1.88, 7.62, and 1.21; and 2.05, 0, and 6.07kg per animal daily. Three mature fistulated wether sheep were fed 6 liters of liquid whey daily, and three similar sheep were fed water only. Rumen liquor samples were taken for analysis of volatile fatty acids at 0, 3, and 6h after whey feeding on each of three alternate days. Alfalfa hay (1.2 kg/animal daily) was fed after the 6-h sampling. Molar percentage of acetic and valeric acids were lower and for butyric acid was higher for sheep fed whey. Propionic acid, acetate:propionate ratio, and total concentration were not affected significantly by whey feeding. Acetic acid decreased from 0 to 3h, then partly returned to the prefeeding level at 6h. The reverse was true for butyric acid. Valeric acid and total concentration of volatile fatty acids decreased from 0 to 6h. Effects of day were unexplained.

Nitrogen metabolism in the ovine stomach: 2. Factors influencing ruminal ammonia levels in sheep maintained on different diets

SUMMARYFactors which could be expected to influence levels of ammonia in the rumen were compared in sheep maintained on diets providing 11·4 or 20·7 g N/day.The ruminal fluid volume in sheep given the lower-N ration was 78% of that in sheep maintained on the higher-N diet. The effect of this in diluting rumen ammonia from recycled urea is discussed.Ruminal urease activity was higher in sheep given the lower-N diet, and was confined to the particulate fraction of rumen liquor in animals given either diet. At least 95% of the maximum activity occurred in the range of pH 5·4–7·05, and pH 6·0–7·25 in sheep maintained on the lower- and higher-N diets respectively. Small variations in activity were observed between the morning and evening meals.In vitro rates of net ammonia production in samples of rumen liquor were similar in sheep given either diet; a positive correlation with the initial ammonia concentration was evident. Net utilization of ammonia was detected in some experiments in samples from sheep maintained on the lower-N diet. Starvation for 1 day was associated with increased rates of production and initial concentrations of ammonia.Cellulose, as cotton thread, was digested at similar rates in vivo in sheep given the different diets. This is discussed in relation to the demand for ammonia by cellulolytic bacteria.

Rumen Liquor pH, Osmolality and Volatile Fatty Acid Changes in Calves Fed Intensively on Barley with Hay Added

SUMMARY Rumen liquor samples were removed from calves during their period of adaptation to a ration containing 87 · 5 per cent barley, 10 · 0 per cent protein and a mineral and vitamin supplement, together with 1 lb of hay for each calf every day. This rumen liquor was examined to determine alterations to pH, osmolality and volatile fatty acid (VFA) fractions present. The rumen liquor pH determined from the barley and hay fed calves was lower than their controls, but it was not as low as that recorded from similar experiments where hay was omitted from the diet. The presence of a biphasic rumen osmolality pattern during this period may at first reflect fluid movement from the rumen immediately the ration alteration commenced. The later peak may be a consequence of fermentation associated with the increasing quantity of food consumed. The volatile fatty acid concentrations and proportions reflect the cereal content of the ration. The correlation of rumen pH and VFA in a “fully adapted” calf may be the result of completed adaptations to the new diet. The influence on the rumen liquor environment of the addition of 1 lb of hay daily for each calf is discussed.

Whole wheat grain feeding of lambs. III. Rumen metabolic responses and animal physiological adjustment to mineral buffer supplements

An intensive 17-week study was made of nine rumen-cannulated crossbred lambs off pasture when given mineral buffer supplements as they were changed from lucerne chaff diets to diets of whole wheat grain plus 2 % of ground limestone. Diets were given ad libitum. Buffers were supplied during transition (period 11) and after transition (period III). The buffers were a 1/1/1/1 mixture of powdered disodium hydrogen phosphate, sodium bicarbonate, potassium bicarbonate, and calciuns hydrogen phosphate given as 2% of the grain offered (group B) and powdered alumirn~~m hydroxide (Al(OH)3) given as 1 % by weight of the grain ofiered (group C). The wheat gram diet was low in sodium (0 008%) and contained 1.50% nitrogen. Production responses to both mineral buffer treatments resulted. Soth buffer treatments increased the voluntary intake (P < 0.01) of wheat above that of the control animals. The rate of eating (g/hr) and pattern of eating did not differ significantly between groups, or between periods I (lucerne chaff) and 111 (post-transition). Groups B and C increased in liveweight to a greater extent than did control animals (P < 0 01) and had heavier carcasses (P <0.01). Results with the mineral mixture given to group B (above) confirm our earlier report. Ingestion of aluminium hydroxide was associated with abomasal ulceration. No significant differences were found between groups in any period for total volatile fatty acids in rumen liquor. Towards the end of period 111, animals given buffer had lower proportions of acetic and higher proportions of propionic acid than did control animals (P < 0.01). Hexanoic acid was detected in all rumen liquor samples obtained in period 111, sometimes in amounts equal to 17 % of total volatile fatty acids. Lactic acid was not detected in rumen liquor in period I, but was present in large amounts in all lambs during period 11, and in lesser but substantial amounts in all lambs during period III. Levels of lactic acid in the rumen liquor in animals receiving mineral buffer supplements fell at a faster rate during period I11 ?hall did levels in control animals. There was a significant decline in rumen pH values for all groups from period I to period III (P < 0.01). Significant rumen pH differences attributable to mineral buffer treatment were apparent (P < 0 05). Buffers were associated with a less acid rumen condition than found in control animals. Relative to control animals, animals given mineral buffers showed increases in rumen buffering capacity and salivary flow rates, and an increased buffering index of the total mixed saliva. Period effects were apparent. The saliva flow rates of control lambs fed on wheat were significantly increased compared with their flow rates on the roughage diet of lucerne chaff. In general, supplementation with aluminium hydroxide and with the mixed buffer respectively yielded similar patterns of response. It is concluded that responses were not primarily due to the sodium level of the diet per se, and that alterations in the animals' electrolyte and acid-base physiology induced by buffer treatment might be contributory factors. Various possible physiological mechanisms are discussed.

Diurnal Variations in Blood and Rumen Metabolites and Feeding Activity of Dairy Steers Under Controlled Lighting

Photographic evidence of diurnal eating patterns of five steers allowed free access to hay in an environment free of natural light were recorded during 37, 24-hour periods preceded by a 14-day preliminary period. Four replicate collections of rumen liquor, jugular blood, and carotid blood were obtained at 2-hour intervals. Rumen liquor samples were analyzed for acetic, propionie, and butyric acid concentrations as well as for pH. Blood samples were analyzed for volatile fatty acids, reducing substances, and ketones. The greatest concentration of eating activity occurred during two periods peaking at 0600 and 1630 hours. Smaller peaks were noted at 0930 and 1430 hours. Only rumen pH and jugular β-hydroxybutyrate were significantly correlated (.476 and −.243) with eating activity. Generally, the steers stopped eating before detectable rises in metabolite concentration. However, periods of maximum metabolite concentration were associated with periods of relatively little eating. These data do not preclude metabolite Concentration as a factor in the regulation of ruminant feed intake patterns.

Forage Digestibility and Diet of Deer on Southern Upland Range

Four white-tailed deer ( Odocoileus virginisnus) were shot from a mixed pinhardwood habi- tat in east Texas at each of six consecutive 10-week intervals. Browse items made up at least 19 percent of the diet in all seasons. Forbs were important dietary constituents in May, mushrooms in July, and acorns in autumn. Acetic acid:propionic acid ratios in rumen liquor samples were wider in the spring after a poor mast year (4:1) than during other seasons (2:1). More gas (S ml gas per gram of solids per hour) was produced in controlled fennentations of rumino-reticular (R-R) contents of deer feeding on acorns than on othejr dietary items. In in vitro digestion trials, composited mixed browse, mixed forbs, mixed grasses, and loblolly pine (Pinus taedu) samples were generally highest in nutrient quality during spring. Grasses and forbs were significantly less digestible rhen mature than when imnlature. Forbs were digested better than were browse or pine tissues. Dead leaves were poorly digested. Green grasses selected during the winter were as digestible as those growing during spring and summer. For- ages most refractory to microbial fermentation had higher lignin:acid-detergent fiber (ADF) ratios than other foodstuffs.

Bifid bacteria in bovine rumen

About 500 bifid isolates from 150 samples of bovine rumen liquor were examined for their morphology, physiology and biochemistry. Diagnosis as “bifid bacteria” was based upon the peculiar pathway of glucose anaerobic metabolism i.e. the fructose-6-phosphate shunt. Four phenetic types were recognized. These types can be differentiated from those found in human habitats because their cell-free extracts are aldolase and HMP dehydrogenases positive: they are potential heterofermenters; furthermore the rumen types are nutritionally different. The distinction of the rumen bifids from the Bifidobacterium species of the intestine of Apis mellifica and Apis indica is still more consistent for a lot of characters. The characters of two rumen types warranted the creation of two new species of the genus Bifidobacterium. One of these, B. globosum n. sp., has a proper morphology, is serologically distinct and has a deoxyribonucleic acid base composition, in % GC, of 64.5. The other, B. ruminale n. sp., found so far only in rumen, is characteristically lactose non fermenter, at variance with all the bifids from human habitats and has peculiar morphological traits. A third type is probably a rough variant of B. ruminale and a fourth is serologically distinct and mannitol fermenter; their taxonomic definition is still, however, premature.

The growth of lambs grazing tall fescue receiving high and low levels of nitrogen fertilizer

1. The growth of lambs grazing tall fescue pastures, receiving high and low levels of nitrogen fertilizer, was studied.2. fertilizer, was studied. final body composition was estimated. Rumen liquor samples were collected three times and herbage intake estimated five times during the 88-day experiment.3. On clipped herbage samples, O.M. digestibility was estimated in vitro, and chemical composition was determined.4. Live-weight gain, final body composition and D.o.m. intake did not differ significantly between treatments. Molar proportions of acetic acid were higher and n-butyric acid lower on the high nitrogen treatment.

Short‐chain fatty acid analysis—A comparison between two gas‐chromatography methods

AbstractThe compositions of a number of known mixtures of volatile fatty acids in aqueous solution and of volatile fatty acids in samples of rumen liquor were estimated by two gas‐liquid chromatographic procedures, one of which operated in conjunction with an automatic titrating device and the other with a flame‐ionisation detector. It was found that the method using flame‐ionisation as the system of detection was more accurate and yielded results more rapidly than did that in which automatic titration was employed.

Bloat in cattle

Abstract Apparatus for foam separation, and its application to the isolation of surface active components of rumen liquor, are described in detail. Preliminary results demonstrate that foam fractions of rumen liquor drawn prior to bloating, and non-bloating feeds of red clover, show differences in concentrations of non-acid lipid, fatty acid, and carbohydrate components that are not reflected in the rumen liquor samples themselves. Foam separation has been used to isolate saponins from rumen liquor Yellow bubbles containing more than 30% lipid were found present in the leading fraction of foam separated from rumen liquor drawn prior to feeding. There were more present when bloat resulted from the following feed than when no bloat occurred. Yellow bubbles were also observed in foam obtained from bloated cattle.

Sampling the contents of the rumen of the dairy cow

Abstract Dairy cows fed pasture were used to compare the concentrations of the volatile fatty acids and the proportions of the individual acids in rumen liquor, obtained by two methods of sampling. Samples of rumen liquor were taken from the middle of the rumen and from the contents, after their removal from the rumen and thorough mixing. Ten samples were taken prior to feeding, and a further 10 were taken 2.5 to three hours after the commencement of feeding. Differences in the concentrations of the volatile fatty acids and the proportions of the individual acids were small between the two methods of sampling. It was concluded that, for pasture-fed dairy cows, a sample taken from the middle of the rumen was reasonably representative of the contents as a whole.

Enumeration of rumen micro-organisms.

SUMMARY: Techniques are described for counting and differentiating the rumen microbial population. The rumen liquor is fixed and preserved in formol saline, and counts are made in two counting chambers, whose dimensions depend on the size of the organism to be counted; stained smears of the bacteria are also examined. Counts made on small samples of rumen liquor obtained through a fistula have been compared with counts on samples of the entire rumen contents; the ratio of these counts seemed to depend on the particular organism counted, the ration and the time after feeding. The importance of differential as opposed to total counts is emphasized.

Studies on the production of volatile fatty acids from grass by rumen liquor in an artificial rumen: I. The volatile acid production from fresh grass

1. A study has been made over two growing seasons of the volatile fatty acid production from ley grass obtained from a single area of one field, under the action of rumen liquorin vitro.2. The acida estimated were acetic, propionic, butyric, valeric and caproic. On only one occasion did the last named appear in measurable amount.3. The main acid produced in early stages of the year is acetic acid, but as the season advances propionic acid becomes the acid of major production.4. In parallel cellulose runs it was found that propionic acid was invariably produced in greater amount than any other acid.5. An attempt has been made to eliminate, by using cellulose as a standard, the effects of using different rumen liquor samples.6. The dried samples, corresponding to the fresh material, were invariably found to yield acetic acid in greater proportion than propionic acid. The average percentages of acids obtained from the dried grass were similar to those found by other workers. It is suggested that the variations between the fresh and dried grass results are due to changes in carbohydrate content resultant upon storage of the latter.