16 BULLETIN 459, U. S. DEPARTMENT OF AGRICULTURE. 
amounts of digestible protein’ which should be contained in the 
rations of cattle and sheep at different ages to insure satisfactory 
growth. These estimates are contained in the following table. They 
are expressed in pounds per head and include the maintenance require- 
ment. As a matter of convenience, the table also contains the esti- 
mated net energy values required per head for normal growth, and 
it thus constitutes a set of approximate feeding standards. In their 
use the weight rather than the age of the animal should be the con- 
trolling factor. 
Estimated requirements 1 per day and head. 
FOR GROWING CATTLE. 
| Beef breeds. Dairy breeds. 
Age. 4 | l 
Live Digestible | Net energy Live Digestible | Net energy 
weight. protein. value. weight. protein. value. 
Months Pounds. Pounds. Therms. Pounds. Pounds. Therms. 
3 200 0.8 4.2 165 . 65 3.6 
6 350 1.10 5.0 275 . 85 4.1 
9 450 25 Dae 325 - 90 4.4 
12 550 1. 40 6.5 400 1.00 5. 
18 750 1. 50 8.2 550 1.10 6.4 
24 900 1. 60 9.3 7 1.20 7.6 
30 1,000 1. 60 9.9 800 1. 20 8.2 
FOR GROWING SHEEP. 
Mutton breeds. Wool breeds. | 
Age. 
Live Digestible | Net energy Live Digestible | Net energy 
~weight. protein. value. weight. protein. value. 
Months. Pounds. Pounds. Therms. Pounds. Pounds. Therms. 
6 72 5) 
12 0. 31 1.05 65 0. 28 0.95 
9 98 21 1.20 82 - 23 Sets0o 
12 115 . 24 1.35 90 . 20 1.15 
15 130 . 24 1.50 95 .18 1.18 
18 150 .23 1. 65 100 15 1. 20 
1 Including the maintenance requirement. 
No satisfactory data for colts are available, while, as noted on page 
10, our knowledge of the relative values of feeding stuffs for swine is 
somewhat deficient. 
REQUIREMENTS FOR FATTENING. 
The foregoing data refer to what might be called normal growth, in 
which the animals are kept in a good thrifty condition, but do not 
become fat. If any considerable fattening is desirable, somewhat 
heavier rations must be given in proportion to the amount of gain 
made, because the increase gain in fattening animals consists to 
a very large extent of fat and therefore means the storing up by the 
animal of more reserve energy. For fairly mature fattening ani- 
