1888.] PUBLIC DOCUMENT — No. 33. 57 



mals on trial was controlled by their individual appetite, — 

 beginning with eight and twelve ounces of meal to four 

 quarts of milk and closing with a daily ration consisting, 

 in case of one lot of animals, of ninety-one ounces of corn 

 meal and twelve quarts of buttermilk per head, and in case 

 of the other, of one hundred and eight ounces of corn meal 

 to seven quarts of skim-milk. The changes regarding the 

 quantity of the daily supply of feed were, for obvious rea- 

 sons, gradual and depending on the appetite of each animal. 

 The alterations regarding the character of the daily feed — 

 i. e., the changes in the relative proportion of meal and 

 milk — were made with reference to the stage of growth of 

 the animals on trial. The proportions between meal and 

 milk were changed from four to fi»ve times. These changes 

 consisted in a periodical increase of meal for a given amount 

 of milk ; they were made for the purpose of increasing the 

 amount of non-nitrogenous fodder constituents in the daily 

 diet during the later stages of growth. This course of pre- 

 paring the daily feed was adopted to secure, whenever de- 

 sired, a definite change in the relative proportion of its 

 digestible nitrogenous and non-nitrogenous food constituents. 

 As both kinds of milk used in the experiment contained the 

 nitrogenous food constituents in a much larger proportion 

 (1 :1.8, — 1 :1.9) than the corn meal (1 : 8. 7 6), an increase in 

 the quantity of the latter rendered it possible to regulate, 

 within certain limits, the character (nutritive ratio) of the 

 daily diet, with reference to a desired proportion of both 

 groups of essential food constituents. The experiment ( II. ) 

 began with a daily diet, consisting of skim-milk and corn 

 meal, which contained one part of digestible nitrogenous food 

 constituents to 2 :7 parts of digestible non-nitrogenous food 

 constituents ; this proportion was subsequently altered by an 

 increase in corn meal to 1 :3.1, later on to 1 :3.9, and closed 

 with 1 :5. The animals Avhich served in this particular case 

 varied in weight from 17 to 19 pounds at the beginning of the 

 experiment. The first stated ration was fed until the animals 

 had reached a weight of from 45 to 50 pounds ; the second 

 until they had reached from 90 to 100 pounds, the third until 

 135 to 145 pounds, and the fourth subsequently to the end of 

 the trial. The final summing up of the results of that experi- 



