AGRICULTURAL EXPERIMENT STATION. 71 



We have seen that protein is an indispensable ingredient of cattle 

 foods. Are the fats and carbohydrates? If from the protein can 

 come all the new material, energy and heat needed to nourish and 

 sustain animal life, why be particular about the amount fed, or why 

 take pains to secure a certain relation between the quantities of the 

 different ingredients of the food provided enough is fed? In 

 answering these questions we can appeal partly to the physiological 

 facts and partly to experience. One reason why a diet, consisting 

 mostly or entirely of albuminoids, would not be advisable, even if 

 possible, is that the excretory organs would be unnecessarily bur- 

 dened in throwing off waste products occasioned by the decomposi- 

 tion of the albuminoids, thus causing disease perhaps. 



Moreover, experience shows that even a carnivorous animal will 

 not continue long in a healthful condition if fed a diet of pure albu- 

 minoids, and that the food of herbiverous animals can easily be 

 made so nitrogenous as to create a tendency toward disease. 



While the terms "flesh formers," as applied to albuminoids, and 

 "heat formers," as applied to carbohydrates, do not express the 

 whole truth, yet it is a fact that fat, starch, sugar and allied com- 

 pounds are the natural and economical source of a large part of 

 animal heat, and to some extent of animal fat and muscular power. 

 Science and experience both clearly indicate that these are the 

 peculiar offices of the non-nitrogenous constituents of cattle foods, 

 and that the mixture of food ingredients for which nature has so 

 evidently arranged in the composition of plants, best harmonizes 

 with the laws regulating the maintenance and growth of the animal 

 body. Granting all that goes before, then it is certain, as before 

 stated, that there must be some mixture of food ingredients which 

 secures less waste of material than any other. 



Generally speaking we can feel assured that it is rational to feed 

 carbohydrates to the full extent to which they can prevent the use 

 of protein for any purpose to which it is not indispensable. The 

 unnecessary use of protein would in general increase the cost of 

 feeding, with no corresponding returns. 



On the other hand, if a ration contains less than the quantity of 

 indispensable protein, production will be limited in proportion to the 

 deficit. 



There is, in fact, much less of over-feeding with nitrogenous 

 foods than of under-feeding, although the former mistake may some- 

 times be made where cotton seed meal is freely used. All these 



