18 BULLETIN 459, U. S. DEPARTMENT OF AGRICULTURE. 
Requirements for the production of 1 pound of milk. 
Requirements. 
Fat in milk. 
Digestible | Net energy 
protein. value. 
Pez cent. Pounds. Therms. 
and 0.041 0.19 
3.0 043 21 
ah 045 24 
4.0 - 049 BH | 
4.5 . 052 .29 
5.0 055 32 
5.5 058 34 
6.0 061 36 
6.5 064 39 
7.0 068 41 
REQUIREMENTS FOR WORK. 
Since the horse (or mule) is the usual working animal in the United 
States, consideration will be limited to this animal. 
There is on record a considerable amount of data as to the rela- 
tion between the work performed by the horse and the amount of 
energy necessary to be supplied in the feed. Where large numbers * 
of horses are kept and the work is relatively uniform in amount, it 
is possible to make fairly satisfactory computations from these data, 
although the method is somewhat complicated. The amount of work 
required of farm horses, however, is so varied in amount and kind 
and so difficult of measurement or estimate as regards amount, that 
it is scarcely practicable to base the calculation of rations upon it. 
The table on pages 11-13 probably shows with at least a fair degree 
of accuracy the relative values of different feeding stuffs as sources of 
energy for work production, while the amount to be fed will ordi- 
narily be based upon the observation of the feeder rather than upon 
arithmetical calculations. As a sort of general average, however, 
Kellner recommends the following rations for a 1,000-pound horse, 
the amounts stated including the maintenance requirement: 
Requirements of the working horse. 
Digestible | Net energy 
protein. value. 
Pounds. Therms. 
1.0 
Honlipht Work. ce2ci2 3. 3h eee 9. 80 
oranda work...) 5 hese eas 1.4 12. 40 
For heavy wWwOtk.. 2.2. (22-3 eee 2.0 16. 00 
DRY MATTER IN RATIONS. 
The total volume of feed which an animal requires, although 
rather variable, has its limits. In computing rations the most con- 
venient indication of the bulk of the feeds is the percentage of dry 
