20 
between each cow and her food, and must eliminate the influence of 
that portion of each period which may be considered as a transition 
period from one food to the next. ‘To do this, in our case, we shall 
ignore the first four days after each change of food, and calculate 
our data upon nine days feeding for each food. 
The milk yielded by a cow is dependent upon hereditary charac- 
teristics, and upon the more or less remoteness from the period of 
calving, the tendency being for the milk flow to decrease with the 
distance from calving. In order to determine this normal decrease, 
we have tabulated the milk records of forty native cows and forty 
Ayrshire cows for the five months from calving, with the following 
for average results :— 
Average yield per month. Lbs. 
From calving. 1st mo. 2dmo. 38dmo. 4thmo. dth mo. 
40 Native Cows 790 27 657 587 518 
40 Ayrshire Cows 898 822 745 673 594 
ee 
Ay. for 80 cows 844 V74 701 630 556 
From this table we find that when the average yield per day was 
28 lbs. for the first month, the yields were 26, 23, 21, and 18 lbs. for 
the second, third, fourth and fifth thirty days respectively, or an 
average decrease of about two pounds monthly from the average 
yield of each month. If we were dealing with a large herd, we 
could therefore assume that when there is no appearance of falling 
off in milk yield, as between two successive periods, that the main- 
tenance of the equality of the yield is strong evidence of the action 
of the food supplied being favorable to milk yield, even when no 
actual increase followed its use. When we study individual cows, 
however, we cannot express the normal decrease in milk yield by 
any one figure, but can say only that two pounds decrease in the 
average yield between two successive periods of thirty days each, is 
as likely to be correct as any other figure that can be offered, and 
that probably the loss is no less. This circumstance relating to milk 
yield must be borne in mind in the interpretation of our tables, even 
if we cannot give accurate expression in figures. 
The following table, calculated for nine day periods must furnish 
the material from which our conclusions in regard to the influence 
of the food fed upon our cattle are to be derived. 
Average for Each Cow in Nine Day Periods. CERES. 
Food Consumed. 

Weight Acid Dy _. Sweet Corn Water Milk A.M. 
Eck ont NY St feea Acid Wet Meal drunk yield ‘IK 
lbs. lbs. lbs. Ibs. c.c. - lbs. ibs. Jbs: Ibs. # ct: 
Period I. Dec. 16-24... 762 21.9 74.4 20.0 4.28 
IL. a. Dec.29,Jan.6 758 17.4 18.0 64.6 24.0 4.18 
b. Jan. 7-15. 788 8.8 24.6 §3.4 25.9 3.67 
ce. Jan. 16-24 725 12.9 16.8 51.6 25.1 8.58 
III. Jan.28, Feb.5 750 22.2 78.7, 19.1 352 
lV. a. Feb. 10-18 751 17.7 7.9 75.7 24.8 8-76 
b. Feb. 19-27 741 15.6 7.6 75.0 25.6 3 63 
V.a. Mar. 4-12 746 17.8 7.6 200 77.8 26.4. 3-47 
b. Mar. 13-21 760 18.0 7.2 200 68.6 26.3 3.37 
VI. March 22-80 761 17.1 6.9 400 79.1 24:67 8.387 
VII. a. April 5-13 715 = 9.7 23.0 44.5 20.0 4.00 
b. Apr. 14-22 725 11.4 25.0 58.4 22:2 4,14 
VILL. Apr.27,May5 714 12.7 8.0 59.7 21.2 3.36 
