Jan. 8,1917 
Ewes' Milk 
3i 
A study of Table I shows an interesting condition as regards com¬ 
parisons between breeds. The marked feature is the tendency toward 
variation within breeds rather than between breeds. This is especially 
evident in column 2, which shows the range within breeds. In view 
of this condition, the variations between the breed averages shown in 
column 3 lose most of their significance on account of the small num¬ 
bers available. 
In the totals for all breeds the averages and range for different age 
periods have been shown. These averages are practically equal for any 
age period from 2 to 7 years. The ranges also at different periods of 
age shown in this summary are approximately equal among ewes at 
any period from 2 to 7 years. The suggestions derived from this table 
are strictly in line with those obtained from Table II—that fat is a 
factor which is exceedingly variable in individual ewes regardless of 
breed or age. 
Table II shows ewes that have been tested for two or more years. 
Column 1 shows the number of the animal; columns 2,3, and 4 the fat 
test of milk in a similar number of lactation periods or successive years. 
Table II .—Variation in the fat of the milk of individual ewes in different years 
Animal No. 
1st test. 
2d test. 
3d test. 
Animal No. 
1 st test. 
2d test. 
3d test. 
Per cent. 
Per cent. 
Per cent / 
Per cent. 
Per cent. 
Per cent. 
......... 
3.8 
7 * 5 
126. 
3.4 
4.8 
4 -o 
5 * 3 
7 * 1 
10. 0 
127. 
5.1 
4.6 
Y rn ....... 
6.4 
8.4 
221. 
6.3 
7 * 1 
1 5 °. 
7.8 
6.4 
223. 
3.6 
6.8 
2 °5 .*. 
4. 0 
4.0 
224... 
8.0 
5.5 
9 .* 
TfS 
4.4 
11.4 
83T. 
2.4 
5.8 
4,8 
1 5 <J.. 
4.4 
5 * 2 
84. 
5.0 
5* 6 
7 * ° 
*59 .... 
I^O 
6.4 
3.8 
85.. 
5.6 
5.2 
3,0 
5.1 
6.8 
8.2 
113. 
6.3 
6.4 
T .. 
9.8 
7.0 
115. 
3. 2 
5 - 2 
7*4 
7 * 4 
6.3 
211. 
6.1 
4. 7 
74 .*. 
*6 . 
4* 5 
6.8 
3 - 2 
214 . 
7. 2 
4.1 
* * * * * . . 
TTO - 
2.7 
2.4 
215 . 
3, 7 
4.0 
6.3 
5.2 
218 . 
8.6 
6-1 
7.8 
3. 5 
7. 2 
219 .. 
5.8 
4.9 
3. 5 
5*8 
7.1 
120 .. 
3.3 
4.8 
. 
j()2 . 
4.6 
6.6 
189. 
6. 5 
5 * 2 
6.1 
4.6 
4-3 
194 . 
9.0 
5-8 
T '76 . . . ....... 
9.0 
7. 2 
105. ... 
5 * 7 
6.2 
6.2 
6. 2 
106 .. . 
4.8 
7. 5 
3-6 
■ * * *. 
. 
6. s 
4.9 
197 . 
3.8 
11.4 
4.6 
7.3 
10.4 
200 . 
7.8 
5. 3 
, . 
- ft 
7.0 
5. 7 
147 . 
3 - 0 
5 * 6 
Average . 
5-67 
6.03 
5-81 
* . .. 
The outstanding feature of Table II is the remarkable variation 
obtained in the fat content of individual ewes tested in different lacta¬ 
tion periods. 1 This indicates that no great reliance can be placed on 
single tests of an individual, and that a test must either cover a larger 
number of periods during one lactation of an individual or that it must 
cover an average of a large number of individuals at one period, in order 
to be representative. This latter condition, which is shown in the aver- 
1 Lack of experimental evidence leaves it open to question whether an equal lack of uniformity would 
be obtained in a number of tests made during the same lactation period of an individual. 
