42 DOMESTICATED ANIMALS AND PLANTS 
milk per year up to over 12,000, and from less than 50 pounds 
of butter fat! to over 500 pounds. Manifestly a whole herd like 
the poorer cows would swamp their owner unless prices were 
enormous or unless their food consumption were correspond- 
ingly lower. 
To test this point, the department conducted investigations 
into the relative efficiency of commercial cows on the basis of 
food consumed. Accordingly two or more cows were purchased 
from each of several of the largest commercial herds of the 
state, the aim being in every case to secure the very best and 
the very poorest individuals in the herd, according to the best 
basis of judgment at hand. The yearly record of these cows 
is shown in the following table : 
VARIABILITY OF COWS ON THE BASIS OF FOOD CONSUMPTION 
No. of Total Total Digestible Ratio Ratio 
cou Ciaden milk fat pie eae n+m?> n=f6 
83 Good 11,794 382 7418 0.63 19.42 
84 Poor 8,157 324 6737 0.82 20.79 
85 Good 9,591 406 7532 0.78 18.55 
86 Poor 3,097 119 4998 1.61 42.00 
93 Good 9,473 358 7604 0.80 21.24 
94 Poor 7,845 282 6706 0.85 23.80 
95 Good 14,540 469 8379 0.56 17.08 
96 Poor 7,085 . 324 6871 0.81 21.20 
97 Good 8,562 291 6893 0.80 23.68 
98 Poor 1,401 52 4062 2.88 78.00 
1 By butter fat is meant not butter, but the fat of butter. Commercial butter 
contains about 85 per cent fat, the rest being water, salt, curd, ete. 
2 Numbers by which the cows were designated in the records. 
8 Each group from the same herd. 
* After multiplying number of pounds of fat by 2.4. This represents the 
amount of food digested by each cow. 
5n +m = nutrients divided by milk produced. 
6 n + f = nutrients divided by fat produced. 
