ENERGY VALUES OF RATIONS FOR FARM ANIMALS, 15 
Maintenance requirements of sheep, per day and head. 
| 
Live Digestible ae 
Weight. protein. AIS 
Pounds Pounds. Therms 
20 0. 013 0. 30 
40 - 028 54 
60 - 039 71 
80 - 050 87 
100 - 055 1. 00 
120 . 061 1.13 
140 - 072 25) 
REQUIREMENTS FOR GROWTH. 
While young animals gain in weight faster than do older ones, a 
pound of increase in live weight in the young animal contains much 
more water and less dry matter than in the case of a more mature 
animal. Moreover, the dry matter in the case of the young animal 
contains relatively more protein and less fat, as a rule, than in the 
older one, and fat contains much more chemical energy than protein, 
the proportion being 1 to 1.67. The consequence is that a gain of 1 
pound in live weight represents the stormg up of much less energy 
in the young than in the mature animal, and therefore requires a 
smaller supply of energy in the feed. 
Unfortunately no very extensive determinations of the composi- 
tion and energy values of the increase of live weight In growing 
animals have yet been reported. The following estimates by the 
writer, derived from such data as are available, may serve to give a 
general idea of the requirements per pound of growth of cattle and 
sheep at different ages, but they can not lay claim to any high 
degree of accuracy. The figures refer to normal growth, with no 
considerable fattening. 
Estimated energy value of 1 pound of gain in weight by growing cattle and sheep. 
Net 
Age. energy 
value. 
Months. Therms. 
3 
1.50 
6 1.75 
12 2. 00 
18 2. 50 
24 2.75 
30 3. 00 
The growing animal also requires a sufficient supply of digestible 
protein for maintenance and to supply material for new growth. 
No very systematic study of the latter requirement has yet been made, 
but from the results of a considerable number of practical feeding 
trials it is possible to make a fairly satisfactory estimate of the total 
