40 DOMESTICATED ANIMALS AND PLANTS 
it will be found that some of the rows will yield two and often 
three times as much as others,! all of which proves that some 
varieties or strains will produce fifty bushels as easily as others 
will produce thirty, showing conclusively the need of better 
seed, or rather of the best that is obtainable. 
Professor Fraser, head of the dairy department at the Uni- 
versity of Illinois, has conducted many hundreds of actual tests, 
aiming to secure reliable data on the relative efficiericy of cows. 
These tests are of two general kinds: one conducted away 
from the University on the commercial herds of the state, 
aiming to secure the yearly product with only approximate 
reference to the food consumption ; the other conducted at the 
University under the most careful conditions, and aiming to 
secure records of the nutrients consumed, as well as of the 
milk and fat produced. 
Of the commercial-herd tests something over twelve hundred 
individuals have been tested for periods running from one to 
three years. Their average animal production was 5521 pounds 
of milk and 219 pounds of fat distributed as follows : 
RELATIVE MILK-PRODUCING POWERS OF 1200 Cows FOR ONE YEAR 
Milk Number below} Percent below] Number above} Percent above Average 
2,000 lb. 10 I— 1190 99 + 5554 lb. 
3,000 Ib. 69 6— 1131 94 + 5,704 Ib. 
4,000 |b. 243 20 + 957 80 — 6,092 |b. 
5,000 II. 495 404 705 59 — 6,650 lb. 
6,000 Ib. 753 63 — 447 3% 71322 Ib. 
7,000 |b. 963 80 + 237 20 — 8,081 Ib. 
8,000 lb. 1096 or + 104 9- 8.943 Ib. 
9,000 |b. 1160 97 — 40 3+ 9.770 |b. 
10,000 Ib. 1186 99 — 14 1+ 10,734 Ib. 
11,000 Ib. 1197 3 11,893 Ib. 
12,000 lb. 1199 I 12,117 Ib. 
1 This is an experiment that every student can readily verify, and it is 
recommended that he do it. 
