62 



BETTER DAIRY FARMING 



What we really want to know is their cost in terms of total di- 

 gestible nutrients. Thus, we will calculate the cost of 100 pounds 

 of total digestible nutrients in each feed and rearrange them on 

 that basis. We figure the total digestible nutrients in a ton by 

 multiplying the amount in 100 pounds, as shown in Table I in the 

 appendix, by 20. By dividing the cost per ton by the total diges- 

 tible nutrients per ton, and multiplying the quotient by 100, we 

 get the cost of 100 pounds of total digestible nutrients. 



102. What to buy. — Now, we are ready to decide what to buy. 

 Though hominy costs $1.55 a ton more than corn meal, it is nearly 

 as cheap in terms of total digestible nutrients and we prefer it 

 because it is bulky and a better general feed for the dairy ration. 

 However, we cannot make our mixture entirely of hominy even 

 though it is the cheapest feed shown, for we must have variety and 

 adequate protein content. The protein content will depend on the 

 roughage. Suppose we have mixed hay containing 50 per cent of 

 clover. We should then select a grain mixture containing around 

 20 per cent of protein. This will require a considerable amount of 

 one of the high-protein feeds. Here corn gluten feed is the cheap- 

 est. However, if we add much gluten we will not be watching out 

 for variety, since we have already selected one corn feed in hominy. 

 Therefore, we had better put in some cottonseed. It costs much 

 more than gluten in terms of total digestible nutrients, but it runs 

 nearly twice as high in protein so we will not need to buy much 

 more than half as much to get the protein needed. Finally, let 



