Wear of permanent incisors with age on commercial Australian Angora goat farms

OBJECTIVE: To quantify if, and to what extent, permanent incisor wear differed with age of goat and farm of origin on commercial Australian Angora goat farms. DESIGN: Observations were made on three Angora goat farms in the wheat-sheep zone of Victoria, each managed according to the farmer's practices. Farmers provided a representative flock of does. METHODS: The proportion and pattern of wear of permanent incisors were recorded and percentage wear calculated. After log(y + 10) transformation, a parsimonious general linear model was developed to relate wear to farm and age, with age considered as a continuous variate. RESULTS: The range in wear of the permanent incisors was 0-100%. For each farm, the most parsimonious model for permanent first incisor wear and average wear of all permanent incisors was a separate straight line relating the transformed incisor wear to the age of doe. The models accounted for 66-73% of variance. On each farm the incisor wear was similar and low for ages up to approximately 4 years. On all farms, the amount of incisor wear increased dramatically with age, although the rate of increase differed with each farm. CONCLUSIONS: Permanent incisor wear increased with age of goat and differed with farm of origin. Angora goat farmers need to be aware of the potential for incisor wear to affect doe production and health.

Fabric handle properties of superfine wool fabrics with different fibre curvature, cashmere content and knitting tightness

The handle properties of single jersey fabrics composed of superfine wools (17 μm) of different fibre curvature (114 vs. 74 °/mm) in blends with cashmere (fibre curvature 49 °/mm) were investigated. There were four blend ratios of cashmere (0, 25, 50, 75%) plus 100% cashmere. Each of the nine fibre blend combinations were replicated three times, and each was knitted into three tightness factors. The 81 fabrics were evaluated using the Wool HandleMeter, which measures seven primary handle attributes and Overall handle, and have been calibrated using a panel of experts and a wide variety of commercial fabrics. Results were analysed by ANOVA and general linear modelling. Tightness factor significantly affected all Wool HandleMeter attribute values, with the effect of tightness factor varying according to handle attribute. The Wool HandleMeter was able to detect differences between fabrics composed of superfine wool differing in fibre curvature, with lower fibre curvature wool fabrics having more preferred Overall handle and softer, looser, cooler, lighter and less dry handle attributes at some or all tightness factors compared with fabrics composed of higher fibre curvature superfine wool. Progressively blending cashmere with wool significantly improved Overall handle, increased soft and smooth handle, reduced dry, heavy and tight handle. Linear regression modelling indicated that fabric mass per unit area explained more than 50% of the variance in overall fabric handle and in combination with variations in fabric thickness and yarn elongation could explain 71% of the variance in Overall handle.

Effects of fibre parameters on the ultraviolet protection of fibre assemblies

Ultraviolet (UV) radiation protection is becoming increasingly necessary for human health, and textiles play an important role. The interaction between UV light and textiles is a complex one, involving fibre, yarn and fabric parameters. In this study, an optical model is presented for examining the influences of fibre parameters on the UV protection offered by a bundle of fibres with a given mass. The effects of mean fibre diameter and fibre type on UV absorption were examined. The model was verified with results of UV–visible diffuse reflectance measurements on natural and synthetic fibres. When the mass of fibres was kept constant, within the measurement range in this study, a bundle of fibres with coarser fibres had a lower UV reflectance than that with finer ones. The model accurately predicted factors influencing UV protection, including fibre diameter, fibre transmittance, porosity and refractive index.

Prestressed natural fibre spun yarn reinforced polymer-matrix composites

Abstract We report that a prestressing technique similar to that traditionally used in prestressed concrete can improve the mechanical performance of flax fibre spun yarn reinforced polymer-matrix composites. Prestressing a low twist yarn not only introduces tension to the constituent fibres and compressive stress to the matrix similar as in prestressed concretes, but also causes changes to the yarn structure that lead to the rearrangement of fibres within the yarn. Prestressing increases the fibre packing density in yarn, causes fibre straightening, and reduces fibre obliquity in yarn (improved fibre alignment along yarn axis). All these changes contribute positively to the mechanical properties of the natural fibre yarn reinforced composites. Crown

A systematic study of carbon fibre surface grafting via in situ diazonium generation for improved interfacial shear strength in epoxy matrix composites

A recently established means of surface functionalization of unsized carbon fibres for enhanced compatibility with epoxy resins was optimised and evaluated using interfacial shear stress measurements. Interfacial adhesion has a strong influence on the bulk mechanical properties of composite materials. In this work we report on the optimisation of our aryl diazo-grafting methodology via a series of reagent concentration studies. The fibres functionalised at each concentration are characterised physically (tensile strength, modulus, coefficient of friction, and via AFM), and chemically (XPS). The interfacial shear strength (IFSS) of all treated fibres was determined via the single fibre fragmentation test, using the Kelly-Tyson model. Large increases in IFSS for all concentrations (28-47%) relative to control fibres were observed. We show that halving the reagent concentration increased the coefficient of friction of the fibre and the interfacial shear strength of the composite while resulting in no loss of the key performance characteristics in the treated fibre.

Weathering, fibre strength and colour properties of processed white cashmere

Weathering refers to the degradation of wool fibres that occur during growth from exposure of the fleece to sunlight, water and air. Weathering damage to Merino wool reduces quantities of fibre that are harvested, reduces length in both raw and processed wools, reduces spinning performance and dyeing outcomes. This work aimed to aimed to quantify if and to what extent weathering occurred in 38 lots of commercial dehaired white cashmere and cashmere top sourced from traditional and new origins of production and the extent of any association between weathering and tensile strength properties of the dehaired cashmere and cashmere top. The cashmere was tested for physical properties, bundle tenacity and extension, tristimulus values brightness (Y) and yellowness (Y-Z) and reflectance. Dye uptake was used as an index of weathering. Linear models, relating to weathering, bundle tenacity and Y-Z were fitted to origin and other objective measurements. Mean attributes (range) were: mean fibre diameter, 17.0 μm (13.5–21.3 μm); bundle tenacity of tops, 10.3 cN/tex (8.3–12.9 cN/tex), for dehaired fibre, 10.1 cN/tex (9.1–11.4 cN/tex). Stain uptake varied from 0.92 to 6.34 mg/g fibre indicating a six-fold variation in the extent of weathering. Both the extent of weathering and the bundle tenacity of commercial lots of cashmere were affected by the origin of the cashmere. Increased weathering reduced bundle tenacity, bundle extension, increased the yellowness and reduced reflectance of white cashmere. Bundle tenacity of cashmere declined as fibre diameter variability increased from 20 to 22.5%. For the samples tested, the cashmere from China, Mongolia, Afghanistan and Iran showed more weathering than cashmere from Australia, New Zealand and the USA. The differences in the extent of weathering and of bundle tenacity between cashmere from different origins were of commercial significance.

One Health approach to controlling a Q fever outbreak on an Australian goat farm

A recent outbreak of Q fever was linked to an intensive goat and sheep dairy farm in Victoria, Australia, 2012-2014. Seventeen employees and one family member were confirmed with Q fever over a 28-month period, including two culture-positive cases. The outbreak investigation and management involved a One Health approach with representation from human, animal, environmental and public health. Seroprevalence in non-pregnant milking goats was 15% [95% confidence interval (CI) 7–27]; active infection was confirmed by positive quantitative PCR on several animal specimens. Genotyping of Coxiella burnetii DNA obtained from goat and human specimens was identical by two typing methods. A number of farming practices probably contributed to the outbreak, with similar precipitating factors to the Netherlands outbreak, 2007-2012. Compared to workers in a high-efficiency particulate arrestance (HEPA) filtered factory, administrative staff in an unfiltered adjoining office and those regularly handling goats and kids had 5·49 (95% CI 1·29–23·4) and 5·65 (95% CI 1·09–29·3) times the risk of infection, respectively; suggesting factory workers were protected from windborne spread of organisms. Reduction in the incidence of human cases was achieved through an intensive human vaccination programme plus environmental and biosecurity interventions. Subsequent non-occupational acquisition of Q fever in the spouse of an employee, indicates that infection remains endemic in the goat herd, and remains a challenge to manage without source control.