ENERGY VALUES OF RATIONS FOR FARM ANIMALS. 23 
The cows average 850 pounds per head and have produced in 
previous years an average of 20 pounds of milk per day testing 4 per 
cent of fat. According to the table on page 14, the maintenance 
requirement of such animals per day and head would be approxi- 
mately— | 
ee tilolerprotermsc nts esse Me PCM a ee ae pound.. 0.43 
SWE LE Sua SN HES EE TIE el SN eg aR eal get therms.. 5.40 
For the production of 20 pounds of 4 per cent milk there would be 
needed, according to the estimates on page 18: 
Dicesubleproterm (0:05 X20)... eke ee ee ee ee pound? 24120 
Neen se N20) cna Mink et Bae Ie aL es therms.. 5.4 
The total feed requirements per day and head are therefore: 
Digestible | Net onerey 
protein. value 
Pounds. Therms. 
0. 43 5. 40 
OLA Ge PLOGUCLION Eee ate: tel ote sacellevic cas Sou aties woeeewiowe ware roan Log oe 1.00 5. 40 
HOUR oe cielaua Sion 15 5 ee A Ee eS) 2 nn Re 1, 43 10. 80 
The problem, then, is to find a mixture of the available feeding 
stufis which will yield these amounts of digestible protein and of 
energy, and which shall have a suitable bulk. 
The first step in the construction of a ration is to fix upon the 
amounts of coarse fodders. It is usually desirable to use as large a 
proportion of these as possible, since they are usually cheaper sources 
of food than gram. On the other hand, the amount of them which 
an animal can consume is limited. Much depends upon the individ- 
_ ual animals, and the proper amount can only be told by trial, but we 
should probably aim to get from 12 to 14 pounds of dry matter in the 
form of coarse fodder. Corn forage being a cheap feeding stuff, we 
shall naturally use this freely, with probably some hay for variety. 
By a little trial, we find that 10 pounds of corn forage and 6 pounds 
of clover hay will give us 13.4 pounds of dry matter and the amounts 
of digestible protein and of energy shown below: 
Total dry | Digestible | Net energy 
Kind and amount of feed. met tort protein. ariel 
Pounds. Pounds. Therms. 
Wormbionace ss! OMMOUTESUR eee Va ea ae en a 8.17 0. 23 4.39 
Maxecrmiaye OMOUNGSe ss. 05540 SS JSE Jat dee ee 5. 23 6 Py) 2. 32 
SOLA E rea team ees ee ON Lis AOE Bs 13. 40 52 6. 71 
