Domestication of Livestock
Newsletter No. 51 – Item 1
Wildlife resources: a global account of economic use [1] is a book published in 1996. The aim of the book is to discuss the use of wildlife resources, both from a domestication view point and from a conservation viewpoint.
They discuss the development of domestication of certain species, setting out 4 stages.
- Stage I – kept captive without or with occasional breeding
- Stage II – kept captive with breeding, beginning genetic isolation
- Stage III – kept captive or herded, selective breeding, full genetic isolation, semi-domestication
- Stage IV – fully domesticated, docile, genetical changes, breeds
When viewing the table one can see that Ostrich is classed as Stage II put at 1860 and the longest Stage IV species starting the process of domestication as long ago as before 7,000BC.
These are the full text descriptions of the different stages:
Stage I: The particular species is kept captive in small numbers with or without breeding. This may occur by herding small groups close to man, leaving them to roam freely during the day-time but restricting them by night to simple protective enclosures. Although some breeding may occur during this state, the captive stock requires regular replenishment from the wild and genetic material is still introduced regularly from the reproductive pool of the wild species.
Stage II: The next step in the process of domestication is that the physically contained animals start breeding regularly under the care and supervision of man. As numbers of captive bred or herded individuals increase, interchange of genetic material with animals of the wild population diminishes. Such breeding might go on for many generations without any intentional selection by man.
Stage III: By this stage the captive animal stock has become genetically isolated from the wild population. Selective breeding at this stage may either be deemed unnecessary or is very limited, for example to produce certain colorphases in furbearing animals. Even without selective breeding, such animal stock will gradually undergo morphological, physiological and behavioural changes merely due to the different environmental circumstances.
Stage IV: Full domestication is achieved only by long-term controlled breeding with total isolation from the wild species and the application of varying degrees of husbandry. This results in a close relationship, even interdependency, between the particular animal species and its master. Selective breeding and husbandry aim at the promotion of distinct anatomical physiological characteristics culminating in the formation of different breeds.
Depending on the duration and severity of the selection process, one may distinguish between “domesticated” and “domestic” animals. The former are referred to as “primitive” domestic animals, externally still resembling the progenitor species and behaving like them. Only the latter are truly “man-made” animals which associate freely with man and might bear little resemblance the progenitor species.
Page 13 discusses how domestication has continued developing. As illustrations the authors cited crocodile having moved from Stage I to Stage II, moving from collecting eggs from the wild to an increasing number of farms in recent years and Ostrich farming reaching Stage III in South Africa about 50 years ago. The interesting aspect here is subsequently when farming opened up to the rest of the world, because export of genetic material was illegal in South Africa, the early stock was collected from the wild. This happened in a controlled manner from Zimbabwe, Tanzania and Kenya with some early shipments illegally captured from wild South African stock. Since there has been no meaningful genetic development as yet, with limited domesticated breeding stock left, it could be argued that the Ostrich Industry outside South Africa remains at Stage II.
It is possible to move to Stage IV over a few generations once commercial production commences on an industrial scale.
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[1] Roth, Harald H., and Gu?nter Merz. 1996. Wildlife resources: a global account of economic use. Berlin: Springer Verlag.