3^4 
Journal of Agricultural Research 
Vol. XXIV, No. s 
There was a substantial agreement in composition of the milk of herd 
A and that of herd B in the preliminary period, and the yield was similar. 
It is logical to assume that the composition of the milk of herd B in sub¬ 
sequent periods would have remained fully as constant as that of herd A 
provided the oils and fats fed were without influence. As compared 
with the preliminary period, coconut fat increased the solids o.6i per 
cent and the fat 0.83 per cent, but at a loss of 4.5 pounds of milk a day 
for the period. On peanut oil the milk practically reverted to its original 
composition, with a gain in yield of 1.8 pounds daily over the preliminary 
period. 
By a like comparison, com oil decreased the solids 0.60 per cent and 
the fat 0.37 per cent but with an increased yield of 2.7 pounds of milk, 
and on soybean oil the solids nearly equaled those of the preliminary 
period, with a loss of 0.31 per cent of fat and approximately the same 
yield. 
ANALYSIS OF BUTTER FAT FROM HERD A 
Colantha and Samantha IV were considered as herd A. The cream 
from these two cows was mixed and churned, and samples of butter fat 
were analyzed; but as the maximum range did not exceed a reasonable 
variation for such a physiological product over a period of four months, 
three samples, Aj, A,, and A^o (averaging practically the same as the 10 
samples) were deemed sufficient to fully represent the herd and for sub¬ 
sequent esterification. 
The percentages of total fatty acids in Aj, A^, and A^o were 94.771, 
94.806, and 94.802 (average 94.793) with no appreciable variation, and 
their neutralization numbers were 246.212, 244.913, and 243.878 mgm. 
(average 245.001), with a loss of 2.334 mgm., largely due in advancing 
lactation to a slight increase of insoluble acids at the expense of the 
soluble. The percentages of free fatty acids were 0.772, 0.936, and 0.458 
(average 0.722), indicating a moderate amount of hydrolysis largely due 
to manipulation. The percentages of soluble fatty acids were 7.591, 
7.302, and 7.258 (average 7.384), and their neutralization numbers 
496.614, 491*413, and 498.044 mgm. (average 495*357)* 
The percentages of insoluble fatty acids were 87.180, 87.504, and 87.544 
(average 87.409), and their neutralization numbers 224.409, 224.343, and 
222.806 mgm. (average 223.853), indicating a slight increase in the pro¬ 
portion of high molecular weight acids with advancing lactation. The 
percentages of glycerol were 12.660, 12.576, and 12.586 (average 12.607), 
indicating no marked change. 
As compared with the herd sample (Table I) the average of Ag, Ag, and 
Ajo showed a close agreement in percentage of total, soluble, and insoluble 
fatty acids and glycerol; but the neutralization number of the total fatty 
acids was higher by 0.901 mgm., that of the soluble acids was lower by 
14.262 mgm., and that of the insoluble acids was higher by 1.963 mgm., 
indicating some difference in proportion of constituent acids. 
