THE FEED UNIT SYSTEM 



Ration Compared with Feed-Unit Standard 



81 



According to the feed-unit standard, the cow should receive 1.85 pounds 

 of digestible protein and 14.6 feed units per day; we note that the ration 

 supplies 1.86 pounds digestible protein and 15.3 feed units. It is, there- 

 fore, somewhat higher in feed units than the standard, but the amount of 

 protein tallies perfectly with that called for by the standard. 



The feed-unit system is simple and easily applied. It has been 

 found to give accurate results under ordinary farm conditions, and 

 is scientifically well founded, as has been shown by the fact that the 

 results obtained by this system do not, as a rule, vary from the 

 methods of valuation of feeding stuffs based on their contents of 

 digestible matter or energy values. 2 At least so far as dairy cows 

 and swine are concerned, this system may be depended upon to fur- 

 nish fully as reliable a guide to practical feeding operations as either 

 of the two methods given. It has been adopted to a consider- 

 able extent also in this country, especially in the work of cow- 

 testing associations. 



QUESTIONS 



1. Explain the origin of the feed-unit system. 



2. What are the special advantages of this system, and to what classes 



of farm animals is it especially adapted? 



3. How is the value of pasturage determined in this system? 



4. Give the feed-unit standard for dairy cows. 



5. Formulate a ration for a 1000-pound dairy cow according to this stand- 



ard, using the following feeds: Mixed hay, corn silage, wheat bran, 

 barley, linseed meal. 



6. How does the ration given above agree with the Wolff-Lehmann and 



Armsby standards for milch cows with the same production. 



2 Wisconsin Circular 37, p. 12; Proc. Amer. Soc. Animal Prod. 1914, p. 69. 



