Dec. 1, 1925 
The Maintenance Requirement of Dry Cows 
1081 
SUMMARY 
The net energy required for maintenance by three dry cows was 
determined in a series of respiration calorimeter experiments to be 
4.150, 5.420, and 5.566 therms, respectively, per 1,000 pounds of 
live weight. The lowest value (4.150 therms) is ascribed to the 
individuality of the subject, which was a cow of unusually quiet 
disposition. The other two cows appeared to be in no way unusual, 
ana their maintenance requirements are not abnormally low, though 
appreciably less than Armsby’s published average of 6 therms. It 
would seem, therefore, that this standard figure is sufficiently high. 
Since two of the three determinations of maintenance requirement 
fall within the range of variation of the previous figures lor steers 
published from the institute, there is in these results no definite war¬ 
rant for anticipating the establishment of a maintenance require¬ 
ment for cows differing from that of steers. 
The applicability of these results to feeding under conditions of 
practice is indicated by the fact that the average maintenance re¬ 
quirement of 6 therms of energy for steers, as determined at the 
institute, has been found to be a satisfactory measure of the main¬ 
tenance requirement, under conditions of practice, not only of steers 
but also of cows. 
In these experiments there were gains of energy by all three sub¬ 
jects on rations computed to supply the maintenance requirements 
in accord with the 6-therm average. 
The net-energy value of a ration composed of 40 per cent alfalfa 
hay and 60 per cent grain mixture, the latter consisting of 30 parts 
wheat bran, 30 parts ground oats, 30 parts corn meal, and 10 parts 
old process linseed meal, was found to be 1.418 therms per kilogram 
of dry matter of the ration, as determined by direct measurement of 
the heat production of the animals. 
A method of approximating the apparent digestibility of a ration 
where it is impracticable to collect the dung and urine separately is 
reported. 
LITERATURE CITED 
(1) Armsby, H. P., and Fries, J. A. 
1911. THE INFLUENCE OF TYPE AND OF AGE UPON THE UTILIZATION OF 
feed by cattle. U. S. Dept. Agr., Bur. Anim. Indus. Bui. 
128, 245 p., illus. 
1912. THE MAINTENANCE RATIONS OF FARM ANIMALS. U. S. Dept. Agr., 
Bur. Anim. Indus. Bui. 143, 110 p., illus. 
(3) - 
1917. the nutrition of farm animals. 743 p., illus. New York. 
(4) Fries, J. A., Braman, W. W., and Cochrane, D. C. 
1924. RELATIVE UTILIZATION OF ENERGY IN MILK PRODUCTION AND BODY 
increase of dairy cows. U. S. Dept. Agr. Bul. 1281, 36 p., 
, illus. 
(5) •-and Kriss, M. 
1924. METABOLISM OF CATTLE DURING STANDING AND LYING. Amer. 
Jour. Physiol. 71: 60-83. 
(6) Kriss, M. 
1925. A COMPARISON OF DIRECT AND INDIRECT CALORIMETRY IN INVESTI¬ 
GATIONS with cattle. Jour. Agr. Research 30: 393-406. 
(7) 
1925. AN IMPROVED METHOD OF COMPUTATION OF NET-ENERGY VALUES OF 
feeding stuffs. Jour. Agr. Research 31: 469-484. 
