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Gomez, J. - C. (2005). Species comparative studies and cognitive development. Trends. Cognit. Sci., 9(3), 118–125.
Abstract: The comparative study of infant development and animal cognition brings to cognitive science the promise of insights into the nature and origins of cognitive skills. In this article, I review a recent wave of comparative studies conducted with similar methodologies and similar theoretical frameworks on how two core components of human cognition--object permanence and gaze following--develop in different species. These comparative findings call for an integration of current competing accounts of developmental change. They further suggest that evolution has produced developmental devices capable at the same time of preserving core adaptive components, and opening themselves up to further adaptive change, not only in interaction with the external environment, but also in interaction with other co-developing cognitive systems.
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Smith, D. G., & Pearson, R. A. (2005). A review of the factors affecting the survival of donkeys in semi-arid regions of sub-Saharan Africa. Trop Anim Health Prod, 37 Suppl 1, 1–19.
Abstract: The large fluctuations seen in cattle populations during periods of drought in sub-Saharan Africa are not evident in the donkey population. Donkeys appear to have a survival advantage over cattle that is increasingly recognized by smallholder farmers in their selection of working animals. The donkey's survival advantages arise from both socioeconomic and biological factors. Socioeconomic factors include the maintenance of a low sustainable population of donkeys owing to their single-purpose role and their low social status. Also, because donkeys are not usually used as a meat animal and can provide a regular income as a working animal, they are not slaughtered in response to drought, as are cattle. Donkeys have a range of physiological and behavioural adaptations that individually provide small survival advantages over cattle but collectively may make a large difference to whether or not they survive drought. Donkeys have lower maintenance costs as a result of their size and spend less energy while foraging for food; lower energy costs result in a lower dry matter intake (DMI) requirement. In donkeys, low-quality diets are digested almost as efficiently as in ruminants and, because of a highly selective feeding strategy, the quality of diet obtained by donkeys in a given pasture is higher than that obtained by cattle. Lower energy costs of walking, longer foraging times per day and ability to tolerate thirst may allow donkeys to access more remote, under-utilized sources of forage that are inaccessible to cattle on rangeland. As donkeys become a more popular choice of working animal for farmers, specific management practices need to be devised that allow donkeys to fully maximize their natural survival advantages.
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Hughes, K. L., & Sulaiman, I. (1987). The ecology of Rhodococcus equi and physicochemical influences on growth. Vet Microbiol, 14(3), 241–250.
Abstract: Growth of Rhodococcus equi was studied in vitro. Optimal growth occurred under aerobic conditions between pH 7.0 and 8.5, at 30 degrees C. R. equi survived better in a neutral soil (pH 7.3) than it did in two acid soils (pH less than 5.5). It grew substantially better in soils enriched with faeces than in soils alone. Simple organic acids in horse dung, especially acetate and propionate, appear to be important in supporting growth of R. equi in the environment. The ecology of R. equi can be best explained by an environmental cycle allowing its proliferation in dung, influenced by management, grazing behaviour and prevailing climatic conditions. Preventive measures should be aimed at reducing or avoiding focal areas of faecal contamination in the environment.
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Takai, S., Narita, K., Ando, K., & Tsubaki, S. (1986). Ecology of Rhodococcus (Corynebacterium) equi in soil on a horse-breeding farm. Vet Microbiol, 12(2), 169–177.
Abstract: The ecology of Rhodococcus (Corynebacterium) equi in soil was studied on a horse-breeding farm. R. equi was cultured from soil at a depth of 0, 10, and 20 cm on the six sites of the farm at monthly intervals for 10 months from March to December of 1983. The highest numbers of R. equi were found in the surface soil. The mean number of bacteria in soil samples at every depth increased remarkably from 0 or 10(2) to 10(4) colony-forming units (CFU) g-1 of soil in the middle of April, and later decreased gradually. R. equi inoculated into six soil exudate broths prepared from surface soils at separate sites yielded suspensions with different optical densities, indicating differences in growth. The distribution of serotypes in the soil was similar to that in the horses on the farm. These findings indicated that R. equi could multiply in the soil and flourish in the cycle existing between horses and their soil environment.
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Barton, M. D., & Hughes, K. L. (1984). Ecology of Rhodococcus equi. Vet Microbiol, 9(1), 65–76.
Abstract: A selective broth enrichment technique was used to study the distribution of Rhodococcus equi in soil and grazing animals. Rhodococcus equi was isolated from 54% of soils examined and from the gut contents, rectal faeces and dung of all grazing herbivorous species examined. Rhodococcus equi was not isolated from the faeces or dung of penned animals which did not have access to grazing. The isolation rate from dung was much higher than from other samples and this was found to be due to the ability of R. equi to multiply more readily in dung. Delayed hypersensitivity tests were carried out on horses, sheep and cattle, but only horses reacted significantly. The physiological characteristics of R. equi and the nature of its distribution in the environment suggested that R. equi is a soil organism.
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Hutchinson, G. W., Abba, S. A., & Mfitilodze, M. W. (1989). Seasonal translation of equine strongyle infective larvae to herbage in tropical Australia. Vet Parasitol, 33(3-4), 251–263.
Abstract: Longevity in faeces, migration to and survival on herbage of mixed strongyle infective larvae (approximately 70% cyathostomes: 30% large strongyles) from experimentally deposited horse faeces was studied in the dry tropical region of North Queensland for up to 2 years. Larvae were recovered from faeces deposited during hot dry weather for a maximum of 12 weeks, up to 32 weeks in cool conditions, but less than 8 weeks in hot wet summer. Translation to herbage was mainly limited to the hot wet season (December-March), except when unseasonal winter rainfall of 40-50 mm per month in July and August allowed some additional migration. Survival on pasture was estimated at 2-4 weeks in the summer wet season and 8-12 weeks in the autumn-winter dry season (April-August). Hot dry spring weather (pre-wet season) was the most unfavourable for larval development, migration and survival. Peak counts of up to 60,000 larvae kg-1 dry herbage were recorded. The seasonal nature of pasture contamination allowed the development of rational anthelmintic control programs based on larval ecology.
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Eisgruber, H., & Stolle, F. A. (1992). [Clostridia in carcasses and fresh meat--a literature review]. Zentralbl Veterinarmed B, 39(10), 746–754.
Abstract: Clostridia are of large clinical importance as well as in the field of food hygiene, where they are responsible for spoilage but they also have a certain significance as food poisoning organisms. Information on the ecology of Clostridia in samples of deep muscle tissue of slaughtered animals is insufficient. This article is intended to increase the knowledge on the occurrence of different Clostridia species in slaughtered animals. The main emphasis is put on the significance of clostridia in meat hygiene. The theoretical basis of the so called original content of microorganisms (intrinsic bacteria), the factors and pathways of Clostridia spreading in muscles and organs are demonstrated.
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