ANIMAL GROWTH AND NUTRITION. 219 



of dollars. Excusing myself from a methodical discussion of 

 the subject, I propose to review some of the laws of animal 

 growth and nutrition, and state facts, accumulated from per- 

 sonal work and the work of others, that bear directly upon 

 economical animal growth. 



For my purpose, a review of some fundamental facts, for 

 those who are not familiar with them, will be both suggestive 

 and important. 



The above table reveals facts in part commonly under- 

 stood, and suggests the inquiry whether the calf, containing 

 more proteine than fat, needs to be fed like the ox, containing 

 twice the amount of fat that it has of proteine. The propor- 

 tion of phosphoric acid and lime, of fat and proteine, to the 

 water of the calf, indicates the progressive changes it must 

 undergo before the period of maturity ; and the difference 

 between the calf and the lean ox or the pig leads us to the 

 conclusion that animals so unlike should not be fed alike, 

 and that the same animal should be nourished differently at 

 varying stages of its growth. A mature animal is making 

 neither proteine nor fat, but maintaining the action of diges- 

 tive and vital organs and heat of body only. Again, we 

 have the butter-cow and ox at work, the growing steer and 

 the fattening steer. These considerations show that feeding 

 is a complex science, requiring skill of a high order. 



COMPOSITION OF FOODS. 



If it is true that animals kept for diverse purposes, or 

 those of differing stages of maturity, require varying pre por- 

 tions of fat, proteine, etc., can these materials, in practice, 

 be given in the specific amounts desired? The following 

 table is made up from analyses of the products that I have 



