Occurrence of peptide and clavine ergot alkaloids in tall fescue grass.

Evidence is presented that ergot alkaloids are ubiquitous in tall fescue pastures infected with the clavicipitaceous fungal endophyte Sphacelia typhina (or Acremonium coenophialum). Ergopeptide alkaloids, predominantly ergovaline, constituted 10 to 50 percent of the total ergot alkaloid concentration, which was as high as 14 milligrams per kilogram in sheaths and 1.5 milligrams per kilogram in blades. Ergot alkaloid concentrations were substantially increased by application of large amounts (10 millimoles per liter) of potassium nitrate or ammonium chloride to infected plants in the greenhouse. The results indicate that ergot alkaloids are probably responsible for the toxicity to cattle of this common pasture and lawn grass and that ergotism-like toxicoses may be caused by clavicipitaceous fungi other than Claviceps.

Protein blotting on nitrocellulose: some important aspects of the resolution and detection of antigens in complex extracts.

The resolution and detection of individual components in complex extracts by protein blotting have been investigated. By probing nitrocellulose transfers with monospecific and multispecific antisera, it was demonstrated that dissociating conditions were required for the maximum resolution of antigens by polyacrylamide gel electrophoresis, a conclusion reinforced by results from 2-D electrophoresis. The dissociating and reducing treatments employed, however, were both shown to be responsible for some loss of total antigenicity and included the complete loss of at least one important antigen. Assays with nitrocelluloses of different pore sizes demonstrated that both higher protein-binding capacities and higher backgrounds were associated with the use of the smallest pore size, while the sensitivity of the assay was greatest when a non-ionic detergent, and not proteins, were used for blocking. Nitrocellulose-bound proteins may be stained with amido black, India ink, toluidine blue, Ponceau S or a gold sol, but these agents do not always give identical staining patterns. While detection of components with immuno-enzyme staining methods had some advantages, problems with non-specific binding were encountered. These did not occur with affinity purified radiolabelled second antibodies, which in combination with scanning of autoradiographs allowed a quantitative approach to be adopted.

Changes in the polynuclear aromatic hydrocarbon content of wheat grain and pasture grassland over the last century from one site in the U.K.

Crops harvested and stored from two long-term agricultural experiments started in the 1840-1850s at Rothamsted Experimental Station (U.K.) have been analyzed for polynuclear aromatic hydrocarbons (PAHs) because PAHs have increased four-to-five fold in the underlying 0-23 cm depth of soil over the last century due to atmospheric deposition. Bulked samples of herbage and wheat grain were analyzed for 16 compounds by gas chromatography-mass spectrometry for groups of years between 1860 and 1986. The sigma PAH (16 PAH) concentrations in herbage ranged between 110 and 6900 micrograms kg-1 dry weight, with fluoranthene, pyrene, benzofluoranthenes (b + j + k), chrysene and triphenylene consistently the most abundant. Benz[a]anthracene, benzo[ghi]perylene, benzo[a]pyrene, benzo[e]pyrene and indeno(1,2,3-cd)pyrene were also all important constituents. PAH concentrations in wheat grain ranged from 4 to 46 micrograms sigma PAH kg-1; the mixture of individual compounds was similar to that in herbage. Correcting for yield differences these corresponded to 37-1500 and 2.4-8.8 micrograms sigma PAH m-2 for herbage and wheat grain respectively. The lowest values were found in the most recent samples (1980s) and the highest for samples collected in 1879-81. Generally, there was a decline in the PAH burden of the vegetation with time. The temporal trends of PAHs in the samples are discussed in the context of possible sources of PAHs. Various lines of evidence indicate that the PAH concentrations in vegetation are an indication of atmospheric deposition directly onto the above-ground plant portions, and that uptake and translocation of soil-bound PAHs is of minor importance.

Assimilation of thorium isotopes into terrestrial vegetation.

Vegetation and root zone soil from 17 locations within and near the boundaries of a former thorium processing plant were collected and analyzed for 232Th, 228Th and 230Th in order to evaluate the degree of movement of these radionuclides from soil to root tissue, as well as the extent of their translocation into above-ground plant compartments. Concentration ratio (CR) values ranged as follows: 232Th: 0.0003-0.3218 (shoots), 0.0065-0.9057 (roots); 228Th: 0.0038-0.3300 (shoots), 0.0183-0.7335 (roots); 230Th: 0.0007-0.4560 (shoots), 0.0076-1.252 (roots). Root/shoot ratios were 1.03-85.6 (232Th), 1.54-45.8 (228Th) and 1.36-54.5 (230Th). In nearly all instances, the CR values for 228Th exceeded those for 232Th, with the average 228Th/232Th CR ratios being 3.36 and 1.68 for shoots and roots, respectively. No discernable difference was observed between 230Th and 232Th concentration patterns. The increased 228Th/232Th CR ratio observed is presumably due to the intake of 228Ra into the plant structure, leading to subsequent production of 228Th, through decay, within the plant. It is estimated that approximately 80% of the resident 228Th in above-ground vegetation originates through this mechanism.

In-vivo estimates for the uptake of caesium-137 by cattle grazing contaminated pasture around the ESK and IRT estuaries, Cumbria, U.K.

Sea water contaminated with diluted radioactive effluent from the Windscale nuclear complex in Cumbria periodically floods low-lying grazing pasture around the estuaries of the rivers Esk, Irt and Mite near Ravenglass. During 1979, an experiment was carried out to measure the transfer of caesium-137 from grass to muscle in cows grazing these pastures. Grass samples were taken in a vivo external gamma-ray measurements were made on cattle. A very low transfer coefficient was found, less than 9 X 10-4 days kg-1 with a best estimate of 4 X 10-4 days kg-1, compared with a more usual value of around 3 X 10-2 days kg-1. The low transfer seems to occur because the bulk of the caesium-137 on the grass is bound to resuspended estuarine surface sediment deposited during flooding. In this form, the caesium-137 is only poorly absorbed across the gut of the grazing cattle.

Transfer of radiocaesium from grass and silage to cows' milk.

The transfer of Cs137 from grass and silage to milk has been followed in detail for one farm in West Cumbria over the year following the deposition from the Chernobyl reactor accident. At this farm about 40% of the Cs137 in milk was attributed to the feeding of silage during the following winter. A wider study of an additional 14 farms showed considerable variations in the contributions from grazing and silage. The transfer quotient from silage to milk was comparable with the values measured for grass over the first few weeks and lower than values reached later in the grazing season.

Transfer of Cs-137 from grass and wilted grass silage to milk of dairy cows.

Deposition of radiocaesium from the Chernobyl reactor accident on the Netherlands made it possible to collect contaminated fresh grass and first cut wilted grass silage. These contaminated roughages were used in transfer experiments with lactating dairy cows to determine transfer coefficients and half-lives for Cs-137 in milk. The experimental design was based on three consecutive periods: a preliminary period to determine the background concentration of the isotope in milk, a contamination period to determine the magnitude of accumulation and finally a depletion period to measure the rate at which the activity concentration of Cs-137 in milk declined after continuous feeding. The average transfer coefficient (Fmilk) for cows fed on contaminated dried grass under steady-state conditions was 0.002 d/kg and for cows fed on slightly contaminated second cut fresh grass 0.006 d/kg. The highest transfer coefficients were obtained for cows fed on contaminated grass silage for 119 days, which also included the dry period of about two months. For the first five days after calving the Fmilk values varied from 0.0066 to 0.0091 d/kg. There were no significant differences in transfer coefficients between cows in early lactation (third month of lactation), cows in late lactation (the last month of the lactation period) and cows fed on both contaminated grass silage and uncontaminated maize silage simultaneously. Half-life values for the rate of decline of the isotope in milk during the depletion period were estimated on the basis of a mathematical model with two exponential components. These components were characterized by half-lives of 0.5 to 3.5 days and 10 to 46 days.

Transfer of Chernobyl fall-out caesium radioisotopes in the cow food chain.

From February to October 1987 samples of milk, grass and other components of the cow diet were regularly collected and analyzed for their radiocaesium contents in 26 sampling stations in a north-eastern region of Italy (Friuli-Venezia Giulia). In this paper we report the feed-to-milk transfer factors for radiocaesium obtained in 13 farms of this region of Italy.

Transfer of Chernobyl 134Cs and 137Cs in cows from silage to milk.

The transfer of Chernobyl Cs-134 and Cs-137 to milk in dairy cows from a diet, predominated by silage, was studied under normal farming conditions. The study was carried out in the period December 1986 till August 1987 and comprised three periods with different levels of radioactive contamination of the silage. Transfer coefficients for both radionuclides were derived from measured radiocaesium concentrations in the diet components and in mixed milk samples. Average silage intake was calculated on basis of total need which depends on milk production. The transfer coefficients calculated for Cs-134 and Cs-137 after a 6 weeks feeding period of high-level post-Chernobyl silage were 0.26 and 0.27% d/l, respectively. These results indicate that a transfer coefficient of 1.2% d/l, from tracer and fallout studies and recommended for predictive purposes, is a conservative estimate in view of the post-Chernobyl experience. The transfer of caesium isotopes from silage to milk in dairy cows is dynamically described with a simple two-compartment model of Pelletier and Voilleque. The most important choices of parameter values to be made in matching calculated and measured concentrations in milk, are those for F and u/m. F is the fraction of ingested activity that is excreted in milk plus urine, and u/m is the ratio between the transfer rates to urine and milk, respectively. The study was carried out with financial support from the Dutch Ministry of Agriculture and Fishery.

Uptake and retention of strontium, iodine and caesium in lowland pasture following continuous or short-term deposition.

Data from the extensive routine environmental monitoring programme around the nuclear reprocessing plant at Sellafield, West Cumbria, are analysed for soil to plant uptake of strontium, iodine and caesium. Relative to the top 10 cm of soil, dry weight concentration ratios derived for lowland pastures for strontium, caesium and iodine are 9, 3 and 2 respectively. Long-term trends indicate a 'spring flush' of activity in vegetation, although this is not statistically significant. Uptake of caesium and iodine is highest generally for mosses and lichen and lowest for grass. The vegetational field loss of these elements over the first 50 days following deposition, is described by: Sr: Reff(t) = 0.7e-0.15t + 0.25e-0.049t + 0.05e-0.011t I: Reff(t) = 0.7e-1.26t + 0.25e-0.17t + 0.05e-0.092t Cs: Reff(t) = 0.6e-0.87t + 0.2e-0.20t + 0.16e-0.065t + 0.04e-0.011t where t is in days. The functions are consistent with the effects of washoff and grazing. Equilibrium plant:soil concentration ratios are established for caesium within about 8 months following short-term deposition. Soil distribution profiles for caesium imply a half-time for transfer through the surface layers of about 6 years.

The transfer of Ag-110m to sheep tissues.

The transfer of Ag-110m from the Chernobyl fallout to sheep tissues is discussed. Ag-110m was only detected in the liver and occasionally the brain of the sheep analysed. The transfer of Ag-110m associated with perennial rye-grass, harvested soon after deposition in 1986, was greater to the liver of both ewes and lambs than that of Cs-137. Transfer coefficients of Ag-110m for lamb liver exceeded those for ewe livers. However, in a 1987 field study there was no difference between transfer coefficients of Ag-110m for ewes and lambs. It is suggested that there is a slow turnover of Ag-110m in the liver of sheep and that unlike radiocaesium, Ag-110m from the Chernobyl fallout did not become more available once incorporated into plant tissues.

Concentrations of Co, Cd, Cr, Ni, and Zn in crop plants cultivated in the vicinity of coal-fired power plants.

In order to determine the effect of airborne emissions of trace elements (Co, Cd, Cr, Ni and Zn) from coal-fired power plants on the environment, concentrations were determined in different species of agricultural plants from the local environment (1-15 km radius) and compared with the corresponding concentrations in soils and fallout. The spatial distribution of trace elements in the soil over 7 years did not indicate any significant increased exposure to plants. In agricultural soils exposed to particle fallout produced by the combustion of brown coal, the trace element content changes slowly; it may decrease owing to its removal with the harvesting of crop plants and due to an insufficient supply of fertilizers. Particle fallout from local power plants is too small to change significantly the natural distribution pattern of trace elements in soils and in plant tissues. For monitoring purposes attention should be paid to the leaves and roots of sugar beet and oat seeds in the vicinity of coal-fired power plants.

Silver-110m and 125Sb in Chernobyl fallout.

Measurements of the two unusual nuclides 110mAg and 125Sb in soils and grass, derived from fallout, were made in Greece after the Chernobyl reactor accident. The 110mAg concentrations ranged from 4.5 to 46.1 Bq kg-1 (average 14.3 Bq kg-1) in soils and from 0.2 to 1.5 Bq kg-1 (average 0.8 Bq kg-1) in grass. The 125Sb concentrations ranged from 15.7 to 284.6 Bq kg-1 (average 105.0 Bq kg-1) in soils and from 1.1 to 19.6 Bq kg-1 (average 4.4 Bq kg-1) in grass.

A field study of the validity of static paper sampling in fluoride pollution surveys.

A field study of fluoride pollution and of its consequences was made over a period of five years in the vicinity of an alumina reduction plant. This study, based upon the use of a static soda impregnated paper sampler, shows that the results obtained are in good agreement with the atmospheric fluoride concentrations obtained with dynamic samplers, especially when fluoride is present in gaseous form (HF). The results suggest that vertically mounted paper samplers are less sensitive to the collection of particulate fluorides. Collection rate is strongly influenced and increases with speed. If this parameter is known, an accurate estimation of the absolute atmospheric concentration is possible; the values shown by this technique are in good correlation with the value (annual mean) of pasture fluoride content. As a correlation exists between pasture fluoride content and the symptoms shown by cattle, the static filter samplers can predict disease in the case of slow chronic fluorosis. The field study agrees with earlier laboratory experiments and shows the validity of these simple and inexpensive types of exposure methods.

The propagation of the Chernobyl 131I impulse through the air- grass- animal- milk pathway in northwestern Greece.

A three-compartment (air- grass-milk) milk contamination model for 131I has been applied to atmospheric, grass and milk data, following the April 1986 nuclear accident at Chernobyl. Samples of ovine and bovine milk collected daily by a large dairy company in Ioannina (northwestern Greece), throughout the month of May 1986 have been employed. The contamination impulse in the area, which provides the input to the model, has been approximated by a first order gamma-variate curve. Transfer rates and decay constants have been extracted by fitting predictions of the model independently to each set of data (air, grass and milk). All model parameters obtained from more than one set of data show remarkable consistency. These parameters are used to calculate the transfer coefficients fm for the transport of radioiodine at equilibrium for sheep and cows.

Radioactivity in environmental samples taken in the Sellafield and Ravenglass areas of West Cumbria, 1977-1982.

Terrestrial foodstuffs and other materials of agricultural importance have been analyzed for fission products and actinides discharged in waste from the Sellafield processing works in west Cumbria . Results obtained between 1977 and 1982 are summarized and it is concluded that the internal radiation exposure of the general public due to consumption of locally produced food in no instance amounts to more than a small fraction of recommended limits. Deposition of seaborne sediment is shown to be the main route by which radionuclides of Sellafield origin reach grazing land bordering a nearby tidal estuary.

Pasture levels of tryptophan in relation to outbreaks of fog fever.

Oral administration of tryptophan induces in cattle clinical signs and lung lesions similar to those of fog fever. Tryptophan assays were performed by a microbiological method on various herbage samples. There was no significant difference in tryptophan content between herbage from two normal pastures and from three pastures in which outbreaks of fog fever occurred.

Comparison of the daily endogenous faecal magnesium excretion from sheep eating grass with high sodium or high potassium concentrations.

Metabolism trials were conducted with two sheep to determine the daily endogenous faecal magnesium excretion and the true magnesium availability of grass which had either a high potassium or a high sodium content. The experiment was conducted as a simple cross-over design and the isotope dilution technique using 28Mg was employed. The sheep ate sodium fertilised grass containing 0-73 per cent Na and 1-55 per cent K and potassium fertilised grass containing 0-15 per cent Na and 3-12 per cent K in the dry matter. The daily endogenous faecal magnesium excretion was not found to be significantly different for each sheep on both grasses; this excretion was approximately 13 per cent of the total faecal magnesium output. The true availability of magnesium was greater in the sodium fertilised grass than in the potassium fertilised grass. It was concluded that the daily endogenous faecal magnesium excretion was not affected by altering the herbage levels of sodium and potassium.

Technical note: sampling technique and drying method effects on chemical composition of tall fescue or fescue-ladino clover pasture samples.

Although esophageal extrusa is the most readily accepted representation of forage consumed by grazing ruminants, esophageal sampling is demanding from the standpoint of animal care and maintenance and extrusa processing. This experiment was conducted with a split-plot design to evaluate the effects of pasture type, pasture sampling technique and drying method on estimation of grazed forage composition. Ten esophageally fistulated steers grazed pastures of either tall fescue (Festuca arundinacea Schreb.) or tall fescue interseeded with ladino clover (Trifolium repens L.); steers were closely observed during four collection periods to determine their exact grazing location. Forage samples were collected either directly from the esophageal fistula (E) or hand-gathered (HG) from the immediate perimeter of the grazed area. Samples of E and HG from each steer were divided and oven-dried at 40 degrees C or lyophilized. Fescue samples had lower (P less than .01) N and ADF N concentrations than fescue-ladino clover samples, and E-collected fescue samples had lower (P less than .05) in vitro digestible OM than E-collected fescue-ladino clover samples. Sampling x drying method interactions were detected (P less than .01) for OM, NDF, ADF, hemicellulose (HEMI), ADL, alkaline peroxide lignin (APL), ADFN and indigestible ADF (IADF). Oven-dried E had higher (P less than .05) NDF, ADF, HEMI, ADL, APL and ADF N than lyophilized E; ADF N and IADF were higher from oven-dried HG than from lyophilized HG. In vitro digestible OM was not modified by oven drying. Hand-gathered samples, whether lyophilized or oven-dried, did not simulate E dried by lyophilization. Standardized collection techniques and drying procedures should be implemented to minimize damage to fibrous components.

Residues in the fat of ewes grazing on soil contaminated with halogenated hydrocarbons.

Three halogenated hydrocarbon compounds were applied to the surface of each of two .57 ha bluegrass plots in October. Each plot was stocked with 10 mature ewes 6 mo after application. Supplemental feed was not offered. Five ewes remained on the plots for 180 d, whereas the other five were removed and replaced at 60-d intervals. Average soil residues for the period of grazing were 13.3, 3.8, 29.3 and 32.8 mg/m2 HCB (hexachlorobenzene), DDE [1,1-dichloro-2,2-bi(p-chlorophenyl)ethylene], DDT [1,1,1-trichloro-2,2-bis-(p-chlorophenyl)ethane] and PBB (polybrominated biphenyls), respectively, for plot 1 and 16.5 and 48.0 mg/m2 DDE and PBB, respectively, for plot 2. Average concentrations of residue in body fat of the five ewes grazing for 180 d were .37, .30 and .30 micrograms/g HCB, DDE and PBB, respectively, for plot 1 and 2.41 and .79 micrograms/g DDE and PBB, respectively, for plot 2. Average residue concentrations in ewes that grazed 60-d subperiods were nearly as great, which indicated that steady state residue levels were reached in less than 180 d. A second trial and was conducted 3 yr later after plowing and reseeding the plots, but only PBB was measured. Polybrominated biphenyl was distributed throughout the top 16 cm of soil but the quantity present had not changed appreciably from the first trial. After seven ewes/plot grazed 136 d, residues were detected in only one of the seven on plot 1, but were detected in all seven on plot 2 with an average concentration of only .032 micrograms/g. It is concluded that concentration of residue in body fat of ewes depended on the concentration of chemical at the soil surface and the amount of soil ingested.