Facial eczema in goats: the toxicity of sporidesmin in goats and its pathology

Groups of six goats were orally dosed with sporidesmin at rates of 0.3, 0.6, 1.2 and 2.4 mg of sporidesmin per kg body weight and their responses up to 6 weeks later compared with those of sheep dosed at the same time. Clinical facial eczema and pathological lesions similar to those found in sheep were found in all the goat breeds, but at higher dose rates of sporidesmin than those which caused equivalent lesions in sheep. Saanens were the most susceptible goat breed, requiring 2-4 times as much sporidesmin as sheep to achieve similar effects. G4 and feral goats required 4-8 times the sheep dose of sporidesmin to obtain similar responses. Gamma-glutamyltransferase reached its highest serum levels after 20 days while glutamate dehydrogenase and aspartate aminotransferase reached their highest levels between 10 and 20 days. Alkaline phosphatase did not rise consistently to high levels in affected goats. The elevation in aspartate aminotransferase levels tended to be early and transient; glutamate dehydrogenase early and prolonged; gamma-glutamyltransferase late and prolonged, and'alkaline phosphatase late and minor. There was considerable individual variation in the time at which elevations occurred and the levels which enzymes reached. Cholesterol and bilirubin levels were high if liver injury was severe.     

Using habitat models to identify suitable sites for marine protected areas for harbour porpoises (Phocoena phocoena)

The harbour porpoise is a highly mobile species and thus represents a considerable challenge in the context of using marine protected areas (MPAs) for conservation. The shelf waters off the west coast of Scotland have been identified as an area of year-round presence, high density in comparison to surrounding areas, and a high young to adult ratio in summer and are thus a suitable area for exploring the location of possible special areas of conservations (SACs) under the EU Habitats Directive. We carried out dedicated surveys over three summers in the southern Inner Hebrides and used generalised additive models (GAMs) to predict areas of high relative density for harbour porpoises for each year. After compensating for survey effects, static bathymetric and persistent hydrographic variables were used in a step-wise model selection procedure. In all years harbour porpoise distribution was best explained by maximum tidal current, with higher densities predicted in areas of low current, and the same high density areas predicted year-on-year. Perimeter-to-area ratio was used to identify which areas should be considered as a basis for designating SACs for harbour porpoise in this area, to form part of the Natura 2000 network. The method used here combines spatial modelling and perimeter-to-area ratio for selecting protected areas, a methodology which is suitable for the protection of other animal species.     

The protective effect of zinc sulphate in experimental sporidesmin poisoning of sheep

Aqueous solutions of zinc sulphate were administered orally to sheep over 5 days (0.125, 0.5 and 2.0 g Zn⁺⁺/sheep/day) to bracket a 3-day period during which sporidesmin also was dosed. The zinc sulphate treatment gave protection from the effects of sporidesmin when compared with control groups dosed sporidesmin alone. Body weight changes were improved and liverdamage scores, numbers of animals showing photosensitisation, serum levels of glutamic oxaloacetic acid transaminase and total bilirubin were lower. The protective effects of zinc sulphate were obtained at levels well abovethose required for growth and maintenance. Protection increased but at a diminishing rate with increasing dose rate of zinc. Because of the small safety margin which exists between the dose rate of zinc sulphate which will provide adequate protection and that which will cause toxicity the use of zinc for the control of facial eczema is not recommended.     

Testosterone serum profile,semen characteristics and testicular biometry of Mangalarga Marchador stallions in a tropical environment

This study was conducted to characterize the daily profile of testosterone secretion and its mean concentrations in the four seasons as well as to evaluate the semen characteristics and testicular biometry of Mangalarga Marchador stallions throughout the year in a tropical region. Three stallions were submitted to semen collections and evaluation of testicular biometry every 14 days along a year. Blood samples were collected once at the middle of each season, in a 20‐min interval during 24 hr in order to evaluate the testosterone secretion profiles among seasons. Testosterone concentrations along the day were higher at the beginning of the afternoon (from 12:00 to 15:00 hr), but a circadian secretion was not clearly observed. Mean testosterone concentrations did not differ among seasons (p > .05), but a pattern of secretion along the day showed variations with higher concentrations in the afternoon during the winter. Ejaculate volume was higher during summer; however, sperm motility decreased in summer and spring. Total sperm in ejaculate, sperm morphology and testicular biometry kept constant along the year showing no differences among the seasons. The results demonstrated that in a tropical region, reproductive aspects of stallions did not show a clearly defined seasonal variation, and months of autumn and winter were not unsuitable for reproduction of the males.     

Linking winter and summer events in a migratory bird by using stable-carbon isotopes

For migratory birds, early arrival and physical condition on the breeding grounds are important determinants of reproductive success and fitness. Differences in arrival times often exceed a month, and later arriving individuals are often in poorer condition. Habitat-specific isotopic signatures indicate that the quality of winter habitats occupied by American redstarts (Setophaga ruticilla) determines their physical condition and spring departure dates, which in turn result in variable arrival schedules and condition on temperate breeding grounds. These findings link events in tropical winter grounds with those in temperate breeding areas for a migratory songbird and provide evidence that winter habitats may be limiting.