MAKUAL OF CATTLE- FEEDING. 367 



Feeding Stajstdard for Mile: Cows, per Day and 1,000 Pounds 



Live Weight. 



Digestible protein. 2.5 pounds. 



'' fat 0.4 •■' 



'* carbhydrates 12.5 ** 



Nutritive ratio „ 1 :5.4 



Total dry matter 24 pounda** 



This means tliat any mixture of suitable feeding-stnffs 

 from wliicli a cow can digest 2.5 ponnds of protein and 13 

 pounds of non>nitrogenous nutrients per day will form a 

 proper ration and yield a good flow^ of milk. 



Advantage of Feeding Standards. — The advantage 

 of a feeding standard lies in the fact that it p]-esents the 

 results obtained by careful experiment and observation in 

 a concise form, and one admitting of practical application. 



Thus the feeding standard for milk cows given above is 

 deduced by Wolff from the results of a large number of 

 experiments made at different times and by different 

 observers In these experiments various feeding-stuffs 

 were used. Now it is plain that a simple statement 

 of the kind and quantity of fodder used in one or all 

 of these experiments would be of use to the feeder 

 only if he had at his disposal the same kind and quality 

 of fodder. If, on the other hand, he must use other feed- 

 ing-stuffs, he can derive no benefit fi*om these experiments 

 unless he has some means of comparing the nutritive value 

 of his feeding-stuffs with that of those there used. 



This he can do by estimating the amounts of the several 

 nutrients which his feeding-stuffs contain in a digestible 



form, since it is evident that their nutritive value lies 

 simply in the amount of protein, fat, and carbhydrates 

 wliicli the cows can extract from them. Moreover, when 

 he knows the quantity of digestible nutrients which his 



