The economics of feeding horses / [Harold A. Woodruff].

  • Woodruff, Harold A.
Date:
1912
Catalogue details

Licence: In copyright

Credit: The economics of feeding horses / [Harold A. Woodruff]. Source: Wellcome Collection.

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    that these food elements have in supplying the wants of the animal. The only satisfactory way to estimate this is in terms of their heat-produeingr power when broken down in the tissues. Proteins, fats, and carbo-hydrates, when fully combined with oxygen, are split up much in the same way that combustible material is burned in a fire, and with a similar result —namely, the production of heat. This heat is capable of conversion into various other forms of energy, such as the muscular energy expended in locomotion; in doing work, as in the case of a draught-horse; in carrymg on the vital bodily processes, such as the movements of the heart and respiratory organs; and in the secretion of the juices from the various glands. ^ All these forms of energy can be estimated and stated in terms of heat, and all are provided for by the food and air taken m by the animal. Thus the heat-producmg capacity of a food is the real measure of its nutritive and work- producing value. In other words, there is a direct proportion between the amount of heat produced by oxidising or burning the nutritive parts of a food and the amount of energy or labour they will sup y after assimilation by a horse or other animal. Many and repeated experiments have been made to ascertain the comparative heat-producing power of the nutritive constituents of food. The principle made use of m these tests is to take a certain amount of the substance under investigation, mix it with an excess of some acWe oxidising agent, such as potassium ch orate, and place the mixture in a metal case or bomb, provided with electric terminals. The bomb is inserted m a special form of water calorimeter (a heat-measuring instmment), and by means of an electric spark the mixture is fused.