Study of wool characteristics in the aranese ovine breed / Estudio de las características de la lana en la raza ovina aranesa

To date, no ethnological study on the wool characteristics of the Spanish Aranese ovine breed has been published. Fifty three animals belonging to this breed are tested as fleece samples. Each sample is analyzed for fleece type and length, yield by isoalcohol scouring, fiber length for each kind of fiber, variation in fiber diameter, and proportions of non-medullated and medullated or kemp fibers. Fiber length appears shorter than that previously reported for the breed by other authors. Fleeces of the Aranese sheep breed can be described as square, simple, "semi-open" and short with a relatively high yield by isoalcohol scouring and low medullation levels, thus indicating good potential quality and greater suitability for potential processing than other similar meat breeds.

Hasta el momento, ningún estudio etnológico sobre las características de la lana de la variedad española ovina Aranesa ha sido publicado. Cincuenta y tres animales de esta raza han sido analizados a partir de muestras de su vellón. Cada muestra se analizó para el tipo de vellón y longitud, su rendimiento mediante isoalcohol desgrasado, longitud de las fibras para cada tipo de fibra, variación en el diámetro de la fibra, y las proporciones de fibras no meduladas y meduladas o fibras kemp. La longitud de las fibras parece más corta que la reportada para esta raza por otros autores. El vellón de la raza ovina Aranesa se puede describir como cuadrado, simple, "semi-abierto" y corto, con un rendimiento relativamente alto por desengrasado mediante isoalcohol y bajos niveles de medulación, lo que indica la buena calidad potencial y mayor oportunidad para el procesamiento potencial que otras razas similares de carne.

Temporal relationship between infestation with lice (Bovicola ovis Schrank) and the development of pruritic behaviour and fleece derangement in sheep.

Pruritic behaviour and deranged fleece are often used as indicators of sheep louse infestation but the exact relationship between infestation and the observation of signs of pruritus was unclear. Two studies were conducted to examine this association. In the first, 24 castrate Merino sheep were randomly assigned to six pens in groups of four and the sheep in three pens infested with 10 lice each on the right mid-side. Louse numbers were counted, fleece derangement scored and pruritic behaviour assessed periodically on each sheep until 38 weeks after infestation. In the second study a single moderately infested sheep was paddocked for 15 weeks with 32 uninfested sheep and louse numbers and fleece derangement monitored for 41 weeks. In the pen studies, differences between infested and non-infested sheep in fleece derangement and pruritic behaviour first became significant (p<0.05) at 8 and 14 weeks, respectively and at louse densities of 0.06 and 0.27 per 10 cm wool part. Some sheep showed definite signs of deranged fleece as early as 5 weeks after initial infestation. In the paddock studies, it took 37 weeks until lice were detected on all sheep in the flock. The correlation between louse numbers and fleece derangement score first became significant (r=0.44 and p<0.05) at 9 weeks after introduction of the lousy sheep, reached a maximum of r=0.79 (p<0.001) at 22 weeks when 84% of sheep had lice detected and the mean louse density was 0.29 per part, and then declined to r=0.12 (n.s.) at 41 weeks when all sheep were infested and the mean louse density was 3.04 per part. It is concluded that fleece derangement is a powerful early indicator of the presence of lice and that sheep may exhibit signs of pruritus well before lice can be readily found by direct inspection. Fleece derangement may be useful as a basis for establishing economic thresholds for the application of long wool treatments in developing louse infestations but appears to be a poor indicator of louse numbers once the infestation is advanced.

Studies on the pathogenesis of shimao zheng (fleece-eating) in sheep and goats.

Research on the disease called shimao zheng, which had resulted in widespread fleece-eating and shedding by sheep and goats in the Haizi area of Akesa County of Gansu Province of China, was carried out by both laboratory studies and pathological observations. There was a marked deficiency of sulfur in the wool and tissues of the affected animals. The pathological changes were mainly loss of fleece, exposure of the skin, keratinization of the epidermal cells, narrowing and reduced numbers of the fleece follicles, and fewer sebaceous glands and sweat glands. Histologically, there was atrophy of the striated and cardiac muscles and of the epithelium of the convoluted tubules of the kidney, together with a glomerulonephritis. The disease was considered to be a local nutritional and metabolic disorder, probably mainly caused by sulfur deficiency.

Prevalence of the causes of fleece derangement among sheep flocks in New South Wales.

An investigation of sheep flocks with unknown histories of fleece derangement, selected at random from the main sheep raising areas of New South Wales, showed that Psorergates ovis was present in 53 of the 177 flocks surveyed and in 162 of the 3495 sheep examined. Of the single causes of fleece derangement, the most prevalent was grass seed contamination (15.7%) followed by infestation with sheep body lice, Bovicola ovis, (14.7%) and infestation with itch mite (7.8%). The prevalence of fleece derangement was significantly higher on sheep in which lice were the only ectoparasites found than on those in which itch mites were the only ectoparasites present. The greatest prevalence of P ovis was in flocks in the Young, Yass, Mudgee and Tenterfield districts. In most affected flocks, more than one potential cause of fleece derangement was present. Itch mite infestation was more prevalent in flocks that received no treatment for ectoparasites than in those that had been treated in the year preceding the survey. Our results did not support a commonly held belief among farmers that arsenical compounds control infestations of itch mites more effectively than other types of pesticides. There was no significant difference in prevalence of fleece derangement between flocks treated with different pesticide groups and those that received no treatment, but mean fleece derangement score was significantly lower in sheep treated with organophosphates than in untreated sheep. Infestations of lice were significantly more prevalent in sheep from flocks treated with synthetic pyrethroids than from those treated with organophosphates or those that received no treatment.

The prevalence of itchmite, Psorergates ovis, among sheep flocks with a history of fleece derangement.

An investigation of sheep flocks in the main sheep raising areas of New South Wales showed that the itchmite Psorergates ovis was frequently associated with fleece derangement. In 26 of the 41 flocks examined, P. ovis was the only ectoparasite detected. P. ovis and the sheep body louse Damalinia ovis, were found in 5 flocks. No external parasites were found on sheep examined from the 10 remaining flocks. The type of fleece derangement most frequently recorded was rubbing which in some cases was combined with areas of chewed fleece. Among flocks, there were positive relations between the prevalence of fleece derangement and prevalence of itchmite or scurf and between itchmite count and mean scurf score. Within flocks, itchmite infested sheep or sheep with scurf had higher prevalences of fleece derangement than sheep on which no mites or no scurf were found. Itchmite infested sheep had a higher prevalence of scurf than those with no detectable mite infestation. There were no significant differences in itchmite populations or fleece derangement between untreated flocks and flocks treated with synthetic pyrethroids, organophosphates or arsenic and rotenone.

Establishing a prognosis for fire damaged sheep.

Twenty, mixed age merino sheep suffering moderate bushfire burns were placed under observation to monitor the effects of the damage and to determine what indicators would provide a prognosis for burnt sheep. Eight sheep died within 29 days of the fire from the effects of their burns, while one which was killed when unable to stand 45 days after the fire had a heavy internal parasite burden. The best indicators that an animal would not survive were immobility and recumbency associated with burns to the hooves and legs below the carpal and tarsal joints which caused swelling and a dry leathery appearance of the skin. Neither burns to the legs not associated with swelling, nor burns to the hooves, head and woolless areas were themselves critical; such affected sheep generally recovered without complication. It was considered that burnt sheep should be assessed daily for the first 10 days. Control of internal parasites and blowflies may be required for recovering groups of sheep. It was found that sheep which survived their burns did not become unthrifty.