THE FEED-UNIT SYSTEM 81 
Ration Compared with Feed-Unit Standard 
Standard 
" Feed| Digestible 
Ration fed ‘niga protein, Feed Digestibe 
. units pounds 
30 pounds corn silage—30 +6 =| '5 42 Maintenance | 6.6 65 
8 pounds clover hay— 8+2=| 4 57 Production ..| 7.2 1.20 
3 pounds corn ...........66. 3 23 aes 
3 pounds gluten feed—3 +.9 =| 3.3 64 Total ..../13.8) 1.85 
Dota 2 ses's’sissadsleisveta eh nen’ 15.3 1.86 
According to the feed-unit standard, the cow should receive 1.85 
pounds of digestible protein and 13.8 feed units per day; we note 
that the ration supplies 1.86 pounds digestible protein and 15.3 
feed units. It is, therefore, 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. 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, and will doubtless be generally adopted in 
the future also in this country, especially in the work of cow-testing 
associations. 
QUESTIONS 
. Explain the origin of the feed-unit system. 
. What are the special advantages of this system, and to what classes of 
farm animals is it especially adapted? 
. How is the value of pasturage determined in this system? 
. Give the feed-unit standard for dairy cows. 
. 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? 
orm co noe 
? Wisconsin Circular 37, p. 12. 
