Prepared by John L. Stone, Assistant Professor of Agronomy, Cornell University, Ithaca, N. Y.
For more than a third of a century, the subject of feeding to farm animals a "balanced ration," or one that conforms quite closely to a "standard" that has been fixed by carefully conducted experiments with the kind of animal for which it is recommended, has been before American stock feeders. The general utility of feeding standards is almost universally admitted by those who have given the matter study, and the number of feeders who are endeavoring to conform their practices to the standards is continually increasing.
The tables of feeding stuffs and the methods of using them have been much simplified of late years, but judging by the large number of requests from farmers, received by the agricultural papers and the Experiment Stations, for formulas of balanced rations, adapted to the needs of the inquirers, the subject is still too complicated, or the labor involved too great, to be readily accomplished by the ordinary farmer. It is with a view of further simplifying the computation of rations and bringing it within the range of every feeder that the accompanying tables have been prepared. The effort has been to carry the computations as near to completion as possible, so that the user will simply need to take from the table the figures corresponding to the kinds and amounts of the feeds used in the proposed ration and add them together, to be able to compare it with the standard. The only advantage claimed for this publication is that, by the arrangement of the tables and by the computations made, the labor of formulating rations is very materially reduced, and it is hoped that many who have not heretofore attempted this work for themselves will be encouraged to do so.
The various substances found in animal bodies may, for convenience, be grouped under four heads: water, ash or mineral matter, fat, and nitrogenous matter or protein. These substances occur in the animal body in somewhat varying proportions, depending upon age, condition, treatment, etc.
Water is an essential constituent of the animal body and constitutes from 40 to 60 per cent of its live weight. Ash occurs mainly in the bones and constitutes from 2 to 5 per cent of the live weight. The fat occurs in greatly varying proportions, but rarely is less than 6 or more than 30 per cent. All those substances containing nitrogen are classed as protein. They constitute an important group, of which washed lean meat and the white of egg may be taken as types. They contain about 16 per cent of the element nitrogen and are the only class into the composition of which this element enters. All the working machinery of the body, such as flesh, skin, bones, hair, internal organs, brain and nerves, contain a large proportion of protein.