A treatise on the diseases and management of sheep : with introductory remarks on their anatomical structure ; and an appendix, containing documents exhibiting the value of the Merino breed of sheep, and their progress in Scotland / by Sir George Steuart Mackenzie, bart.

  • Mackenzie, George Steuart, 1780-1848.
Date:
1810
Catalogue details

Licence: Public Domain Mark

Credit: A treatise on the diseases and management of sheep : with introductory remarks on their anatomical structure ; and an appendix, containing documents exhibiting the value of the Merino breed of sheep, and their progress in Scotland / by Sir George Steuart Mackenzie, bart. Source: Wellcome Collection.

Provider: This material has been provided by the National Library of Medicine (U.S.), through the Medical Heritage Library. The original may be consulted at the National Library of Medicine (U.S.)

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    food, have not only their small guts considerably longer, but also their great guts more capacious than such creatures as feed on other animals. The rea- son of this seems to be, that as animal food is not only much more easily reduced into the nutritious fluid called chyle, but more prone to putrefaction, a long retention of it might be followed by the worst effects ; therefore, such creatures as subsist on animal food, require shorter and less capacious intestinal canals than those which live on vegetables; which being less capable of being dissolved and converted into an animal nature, there is a necessity for ani- mals which feed on them being provided with a long and capacious canal, in order that the food may be considerably retarded in its passage, and be more completely changed. The digestion of the sheep, like that of the cow, and some other animals, is accom- panied by a particular kind of action or process, called rumination ; the intention of which seems to be, that the food may be sufficiently comminuted, and thus be more extensively acted upon by the stomach. It is not observed that a lamb or calf ruminates while it feeds on milk alone; but the operation takes place as they begin to eat solid food. As long as the young animals feed on milk, the food de- scends immediately, along the gutter already men- tioned, into the fourth stomach, without stopping in any of the first three. The rumination does not take place till after the animal has eaten a considera- ble quantity; after which it lies down, if it can do so conveniently, and then begins to chew the cud ; though the operation will also take place in a standing posture. In the action, a ball is observed to rise from, the stomach with great velocity ; this is chewed very accurately, and is then swallowed; another ball is forced up and chewed; and so on, till the whole of the food which the animal has eaten, has undergone the operation. By means of rumination, the animal extracts a much larger proportion of nourishment