476 
Journal of Agricultural Research 
Vol. XXXI, No. 5 
COMPUTATION OF THE GAINS OF ENERGY BY THE ANIMAL AND OF THE TOTAL NET 
ENERGY OF THE RATIONS 
Subtract from the metabolizable energy of the ration the total 
heat production. The remainder is the net energy gained by the 
animal body. This gain may be negative on low rations. Add to 
the energy gained by the animal the average net energy required for 
maintenance. The sum represents the total net energy of the ration. 
Table VI .—Computation of the total net energy of the ration 
Period No. 
Metabo¬ 
lizable 
energy 
Heat pro¬ 
duction 
Gain 
Net en¬ 
ergy for 
mainte¬ 
nance 
Total net 
energy of 
rations 
1........... 
Cals. 
12,061 
20,553 
6,235 
10,157 
Cals. 
10,171 
14,035 
7,780 
9,501 
Cals. 
+1,890 
+6,518 
-1,545 
+656 
Cals. 
5,066 
5,066 
5,066 
5,066 
Cals. 
6,956 
11,584 
3,521 
5,722 
2.......... 
3........... 
4__........ 
COMPUTATION OF THE NET ENERGY PER KILOGRAM OF DRY MATTER, AND OF THE 
PERCENTAGE UTILIZATION OF THE METABOLIZABLE ENERGY OF HAY 
Divide the total net energy of the hay ration by the kilograms of 
dry matter eaten. The result is the net energy value per kilogram 
of dry matter. To get the percentage utilization of the metabo¬ 
lizable energy, divide the total net energy of the hay ration by the 
metabolizable energy of the ration and multiply the result by 100. 
Table VII .—Computation of the net-energy value of timothy hay 
Period No. 
Dry mat¬ 
ter of hay 
eaten 
Metabo¬ 
lizable 
energy of 
ration 
Total net 
energy of 
ration 
Net en¬ 
ergy per 
kilogram 
of dry 
matter 
Utiliza¬ 
tion of the 
metabo¬ 
lizable 
energy 
3______ 
Kgms. 
2.9742 
4.8920 
Cals. 
6,235 
10,157 
Cals. 
3,521 
5,722 
Cals. 
1,184 
1,170 
Per cent 
56.47 
56.34 
4______ 
Average_ 
1,177 
56.40 
COMPUTATION OF THE NET ENERGY PER KILOGRAM OF DRY MATTER, AND OF THE 
PERCENTAGE UTILIZATION OF THE METABOLIZABLE ENERGY OF GRAIN 
Multiply the average net energy value of the hay previously 
determined from the bay rations (Table VII) by the dry matter of 
the hay in the mixed ration, to get the net energy equivalent of the 
hay. Subtract this from the total net energy of the ration. The 
remainder is the net energy of the grain. Divide the net energy of 
the grain by the kilograms of dry matter of grain eaten to get the 
net energy per kilogram of dry matter of grain. Multiply the 
average metabolizable-energy value of the hay by the dry matter 
of hay in the mixed ration, and subtract the result from the total 
metabolizable energy of the ration, to get the metabolizable energy 
of the grain. Divide the net energy of the grain by the metabolizable 
energy of the grain, and multiply the result by 100 to get the per¬ 
centage utilization of the metabolizable energy of the grain. 
