Localization of low-sulfur keratin proteins in the wool follicle using monoclonal antibodies.

Monoclonal antibodies that recognize components of the low-sulfur keratin proteins extracted from Merino wool have been used to locate these components within the wool follicle. Immunoblotting procedures showed that all of the monoclonal antibodies bound more than one of the eight low-sulfur protein components, indicating that these proteins have antigenic determinants in common. Immunofluorescence studies showed that those antibodies specific for the component 7 family of the low-sulfur proteins bound to the developing wool fiber, whereas those antibodies recognizing the component 8 family bound to areas throughout the wool follicle, particularly the inner and outer root sheaths, but also to the fiber, the cuticle, and the epidermis. One of the monoclonal antibodies also bound to intermediate filament networks of cultured human epithelial cells.

Antibodies against merokeratin from sheep wool decorate cytokeratin filaments in non-keratinizing epithelial cells.

Merokeratin is an easily soluble proteolytic derivative of mature alpha-keratin. Guinea pig antibodies have been raised to merokeratin prepared from sheep wool. These antibodies decorate in immunofluorescence microscopy arrays of bundles of intermediate sized filaments present in established epithelial cell lines growing in culture. Thus, the highly helical soluble proteolytic fragments of mature alpha-keratin contains antigenic determinants shared by the cytokeratins present in non-epidermal cells, and antibodies to these keratin fragments can be used for the demonstration of at least some cytokeratin-containing structures in other cells and tissues.

The isolation of wool keratin messenger RNA from sheep.

A method for the isolation of polysomal RNA from plucked wool follicle tissue is described. When translated in a reticulocyte lysate cell-free system, the products encoded by the RNA are electrophoretically identical to the low-sulfur and high-sulfur wool keratins. Since non-keratin translation products were not detected, the keratin mRNA species appear to be the predominant messenger component of the polysomal RNA. Sucrose gradient fractionation of the polysomal RNA gave rise to 2 discrete peaks of keratin mRNA, with mean sizes of 21S and 11S. The 21S fraction coded for the low-sulfur and larger high-sulfur wool keratins, while the 11S fraction coded for proteins smaller than about 20000 daltons, possibly the high-tyrosine keratins and smaller high-sulfur keratins. The keratin mRNA can be separated from the bulk ribosomal RNA by oligo(dT) cellulose chromatography, and hence is presumed to contain a terminal poly(rA) tract.

Patterns of wool moisture in merino sheep and its associated with blowfly strike.

A method for determining the moisture content of wool with a minimum disturbance to the constituents is described. The method was used to show differences in moisture content according to anatomical site, age, sex, strain of merino and in lesions of fleece rot, bacterial stain and active flystrike. The incidence of natural flystrike was recorded and related to the higher levels of moisture content. The moisture content in proximal wool was found to increase at different rates, following wetting of the fleece with droplets of water falling under gravity to simulate rain. A level of 20 per cent moisture content was reached after different time intervals in different strains of merino sheep, which may explain one of the differences in strain susceptibility to fleece rot

Selenium concentration in the blood and wool and glutathione peroxidase activity in the blood of three breeds of sheep.

The activity of the enzyme glutathione peroxidase (GSH-Px) in whole blood and the selenium concentrations in whole blood and wool were measured in samples taken from 15 Scottish Blackface, 16 Welsh Mountain and 16 Finnish landrace sheep. Blood selenium sheep had almost twice the GSH-Px activity and blood selenium concentration of the other two breeds (P less than 0.001). Wool selenium concentrations of the three breeds were not significantly different. Blood selenium concentration and GSH-Px activity were highly correlated (r = 0.8, P less than 0.01) but wool selenium concentration was not significantly correlated with either of these measurements.

The effect of a drying agent (B26) on wool moisture and blowfly strike.

A drying agent (B26) was applied as a mist to sheep fleece. A reduction of 30 per cent in wool moisture was recorded, which persisted for 10 to 12 weeks. Reapplication of B26 extended the period of dryness, without adding to the reduction of moisture. Treatment using 100 to 200 ml of the drying agent resulted in reduced fleece moisture content for seven days when exposed to wetting by simulated rain. Treated sheep showed a 60 per cent reduction in the number and severity of fleece rot lesions. Diazinon reduced the incidence of natural flystrike by 50 per cent and the drying agent by 75 per cent over a five week period before shearing compared with untreated animals.

Effects of double decking and space allowance on the performance and behavior of feeder lambs.

A 2 X 2 factorial experiment was conducted using growing lambs to compare single-level vs double-decked pens and high (.32 m2/lamb) vs low (.48 m2/lamb) densities. Three replicates of each treatment combination were involved using 30 lambs/pen. In the double-decked pens, an upper deck located over the rear section of the lower level provided one-third of the total floor area. Feed and water were provided on the lower level only and lambs could move freely between levels by means of a slatted ramp. All floors were of expanded metal. Use of the various areas of the pens was determined during a 24-h observation and by a videotape recording of the double-decked pens during the daylight hours. Fleece contamination was determined by visual observation and standard wool testing procedures. Gain was determined over the 8-wk period of each replicate. The high density treatment resulted in 1.5 kg/lamb (10%) less gain (P less than .01) and, in the case of double-decked pens, different patterns of space utilization compared with the low density treatment. Lambs in the low density pens were able to move more successfully from resting areas to the feeding area in the afternoon (P less than .01). The double-decked system did not significantly affect weight gain, but resulted in dirtier fleeces (P less than .01).(ABSTRACT TRUNCATED AT 250 WORDS)

Environmental contamination by heavy metals and fluoride in the Saeftinge salt marsh (The Netherlands) and its effect on sheep.

The Saeftinge salt marsh in the Westerschelde estuary (southwestern part of the Netherlands) represents one of the very few tidal brackish marsh ecosystems in Western Europe. From May 1983 to May 1985 the local pollution of this marsh with metals and fluoride was investigated. Samples from soil and vegetation were analysed monthly for cadmium, lead, copper, zinc, manganese, iron, and fluoride. The amount of these substances in the soil appeared to be related to both the percentage of clay particles and organic matter in the soil and to the frequency of tidal submergences. In vegetation, the pollutants clearly showed a seasonal variation. Adherent clay, deposited on the plants during submergences, contributed considerably to the total amount of these elements. Sheep grazing in the marsh were investigated for renal and faecal excretion of these elements, but no relation between these samples and the seasonal variation in vegetation was found. Presumably sheep consumed vegetation selectively, avoiding the more contaminated plants. Regular clinical inspections of the sheep revealed no signs of acute or chronic intoxication. The organs of sheep that died during the investigation showed increased levels of cadmium in the liver and kidney, and iron in the liver, but not enough to cause alarm. Fluoride found in the rib material, although slightly increased, did not indicate fluorosis. In conclusion, contamination with metals and fluoride, as observed in the salt marsh, apparently does not impair the health of locally grazing sheep. This may be due to selective consumption behaviour of the sheep, their stabling during the winter, limited biological availability of the elements studied, and a sheep management adapted to the local circumstances.

Survey of levels of propetamphos and diazinon used to control sheep scab in Northern Ireland.

As a result of an increase in the incidence of sheep scab in Northern Ireland, the concentrations of propetamphos and diazinon were measured during 1987 and 1988 in fleece and liquid dip samples from selected flocks, including some in which inadequate dipping was suspected. Sixty-five per cent and 68 per cent of the liquid dip samples contained less than the manufacturer's recommended maintenance concentrations for propetamphos and diazinon respectively. The concentrations found in fleece were also lower than those found in sheep which were dipped with the recommended concentrations of propetamphos and diazinon in a controlled experiment.

The changes in protein concentration and bacteria of fleece and skin during the development of fleece-rot and body strike in sheep.

The sequence of events in the development of fleece-rot and body strike in sheep is described. When sheep were wetted by rain, vast increases in the numbers on microorganisms on the fleece and skin surface occured. Frequently, only one bacterial genus, Pseudomonas, proliferated and produced a bacteriostat to inhibit the growth of other resident flora. The development of fleece-rot lesions was characterised by a sudden substantial increase od soluble protein, presumably plasma protein, onto the skin surface. Pseudomonas spp proliferated on the skin surface and frequently produced extracellular, green pigment. First instar blowfly larvae were observed subsequently in such lesions.

Observations on fibre diameter variation of sheep in relation to fleece-rot and body strike susceptibility.

A comparative study of various fleece properties known to influence fleece-rot susceptibility was made in a merino flock consisting of sheep which were found to be either resistant or susceptible to fleece-rot and body strike following heavy rains. The fleece properties measured were fibre diameter, fibre diameter, fibre diameter variation, wax content, suint content, wax to suint ratio, suint pH, insoluble nitrogen content, wool colour and wettability. Fibre diameter variation, due mainly to the presence of coarse, secondary fibres in the staple, was the only fleece property which differed significantly (p less than 0.001) between resistant and susceptible animals. The coefficient of variation of fibre diameter was lowered from a mean value of 22.7 +/- 0.3% in susceptible sheep to 20.0 +/- 0.3% in resistant sheep. A causal relationship between high fibre diameter variation and fleece-rot susceptibility is suggested. Sheep with irregular fibre size may retain free moisture in the fleece for longer, and thereby become more susceptible to fleece-rot than sheep with uniform fibre diameter, other predisposing factors being equal.

[Electrophoretic studies of acid mucopolysaccharides in skin, prekeratin of hair follicles and in keratoses of wool]. / Elektroforeticheskoe issledovanie kisl'kh mukopplisakharidov kozhi, prekeratina volosianykh follikulov i keratoz shersti.

Mucopolysaccharide complex isolated from skin, prekeratin of hair follicles and keratoses of wool by paper electrophoresis was separated into chondroitin sulphate and hyaluronic acid. The content of chondroitin sulphate in all the objects under investigation except for gamma-keratosis is higher than that of hyaluronic acid. The highest level of chondroitin-sulphuric acid is observed in the matrix of prekeratin of hair follicles and cuticule of wood fibre, i. e. beta-keratosis.