10 



cow to produce large and continuous milk yields. According to 

 Wolff, if much less than 2.50 pounds daily are fed, the cow will 

 shrink more rapidly in her yield. The quantity of fat is not of so 

 much consequence, the 0.50 pounds being the amount that happened 

 to result from the feed combination necessary to secure the protein 

 and carbohydrates. These quantities of the several nutrients give a 

 proportion of protein to carbohydrates or a nutritive ratio of 1 to 5.4. 

 In other words, for milk production, animals need about five times as 

 much carbohydrates as protein. These proportions cannot of course 

 be followed with mathematical accuracy. Cows differ in their ability 

 to turn feeds to the best account, and the judgment of an experienced 

 feeder is alwaj's necessary if the best results are to be obtained. In 

 all feed combinations palatability must also be carefully considered. 

 If a cow should be fed all she would consume of any palatable dry 

 coarse fodder such as a good quality of hay, she would have at her 

 disposal the following digestible nutrients : 



Protein, Fat, Carbohydrate, Total, Nutritive Ratio, 

 Pounds 1.4 0.4 12.4 14.2 1:9.5 



It is very clear that such a ration lacks in protein, as well as in 

 total digestible matter. In order to overcome these deficiencies, 

 recourse is had to the concentrated feeds rich in protein, and suflBcient 

 are added to increase the protein to the necessary amount. By this 

 addition of concentrated feeds, the necessary total nutrients will 

 also be obtained. The protein is the most costly of the three groups 

 of nutrients. The writer is not sure that it would be economy in all 

 cases to feed 2.50 pounds. It is possiblethat the conditions in many 

 cases are such that two pounds daily would be more economical. In 

 other cases it might be wise to feed as high as three pounds daily. 

 These problems are soon to be investigated. 



(b) FEEDS AND FEED COMBINATIONS FOR THE 

 DAIRY COW. 



Having briefly considered the principles on which a rational system 

 of animal nutrition is based, the next step is to classify the many 

 different cattle feeds and consider their comparative values. 



