Proportion Nutrienis in Worlt-Horse Ration 375 



requiring- high feeding, we must resort to the grains 

 in order to construct a ration of maximum efficiencj'. 



Concerning the nutritive ratio or proportion of pro- 

 tein, in a ration designed for working horses, there is 

 a variety of recommendations. The German standards 

 call for ratios from 1:7 to 1:6, according to the severity- 

 of labor, the daily weight of protein for a 1,000-pound 

 horse to be from 1.5 to 2.5 lbs. This is greatly more 

 protein than is recommended by Lavalard, who, on the 

 basis of extensive experience, declares that 1.15 lbs. 

 of protein daily is sufficient for ordinary work, this to 

 be increased to 1.35 lbs. when the labor becomes more 

 severe. There is one fundamental fact that is pertinent 

 to a discussion of this point, which is that the non- 

 nitrogenous constituents of the ration are largely the 

 source of muscular power. As stated before, it was 

 formerl}- thought that muscular effort was sustained at 

 the expense of muscular tissue, but when it was found 

 that no more urea was excreted by men climbing a 

 mountain than when they were much less active, this 

 view was abandoned. Later researches have clearly 

 shown that when work increases the excretion of car- 

 bon dioxid increases in like proportion, without any 

 important rise in the protein exchange. In other words, 

 the carbohydrates and fats are largely the fuel that 

 supplies energy for mechanical purposes. Common 

 experience ratifies this conclusion of science. How 

 many horses and oxen have successfully endured severe 

 labor on meadow hay, oats and corn, sometimes the 

 grain being largely the latter! 



It is the judgment of the writer that a ration prop- 



