MILK AND BUTTER YIELDS OF HEIFERS 143 


: Daily Increase 
Cop eis in yar of (Based on 7 Day Yield) 
5 14.35 0031 From four to five years. 
+ 1322 .0052 From three to four years. 
3 LbAst 0062 From two to three years. 
2 9.05 



give (9.05+14.35—.631) 63.1%; at three years of age (11.31I- 
eeld-35 771750) 70.070; at four years of age (13.22=14:357-.Q25) 
_ 92.1% of the calculated yield at even age of five years or when 
in mature form. 
3. The calculated yield at even age of three years is 11.31 
pounds of butter-fat, and at two years of age 9.05 pounds of 
butter-fat. The productive capacity at three years was (II.- 
3I—9.05—2.26)2.26 pounds more than at two years of age, 
or at the rate of (2.26+365=.0062) .0062 pound of fat more 
per day. In the same manner the records at four years of 
age are 1.91. pound on fat more than at three years of age, or 
at the rate of .0052 pound more of butter-fat per day. The 
records at five years of age show a production of 14.35 pounds 
of butter-fat, which is 1.13 pound more than at four years of 
age, or at the rate of .0031 pound of butter-fat more per day. 
4. The present requirements for admission to the Holstein- 
Friesian Advanced Registry is 7.2 pounds of butter-fat in 
seven days when calving at two years old or under two years. 
Every day of age from two to three years, from three years 
to four, and from four years to five, increase this requirement 
00439 pound of butter-fat per day. The required increase 
factor, therefore, is uniform for each day older than two 
years. It would appear, from the last column in Table No. 1, 
that the actual daily increase in productive capacity from two 
to three years of age is .0062 pound of fat; from three to four 
years of age .0052 pound of fat, and from four to five years 
of age .0031 pound of fat. 
