Animal nutrition / [Thomas Barlow Wood].

  • Thomas Barlow Wood
Date:
1924
Catalogue details

Licence: In copyright

Credit: Animal nutrition / [Thomas Barlow Wood]. Source: Wellcome Collection.

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    ratio is not a very simple matter. It can only be done correctly by taking into account the actual quantities of protein, etc., in the various ingredients. Attempts at short cuts are almost sure to cause serious errors. Fortunately, such calculations are not necessary. It is easier and more certain to compute the ration MethodtiVe terms of starch equivalent or net energy, and afterwards to check its protein content and adjust the ration if necessary. This is the method adopted in the chapters on rationing. The idea of nutritive ratio is, however, useful in so far as it assists in defining the relative richness of a feeding stuff in protein. To use it in computing rations is very liable to cause serious mistakes. Richness in protein is, however, not the only point to be considered in regard to suitability of com- Ch?rea?teerisrtaics.P0siti0U- An animal can oul*v eat a defiuite amount of bulk per day. The best measure of bulk is the proportion of dry matter. The weight of dry matter which the capacity of the digestive organs of various animals allow them to consume is defined by the curves connecting live weight and food consumption given in Dia¬ grams II. to V. From these curves it is possible to read off the amount of dry matter which an animal of any given live weight will consume per day. This sets a limit to the bulk of the ration. The amount and character of the home-grown contribution to this is next decided, and its composition worked out in terms of dry matter, starch equivalent, and digestible pro¬ tein. It will usually be found that the home-grown contribu¬ tion provides plenty of bulk but is deficient in protein. The supplement to be purchased must, therefore, be not only rich in protein, but also concentrated, that is to say, low in water and fibre. An additional reason for this is that it would not be economical to pay costs of transport on water and fibre which are produced in plenty on the farm in the form of roots and other succulents, and in hay and straw.
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