May s, 1923 
Fatty Acids in Butter Fat 
387 
The percentages of butyric acid in A3, A^, and from cows receiving 
grain and hay, were 3.407, 3.120, and 3.480 (average 3.336); of caproic 
acid 1.731, 1.872, and 2.064 (average 1.889); of caprylic acid 0.810, 0,820, 
and 0.527 (average 0.719); and of capric acid 1.643, i*490, and 1.187 (av¬ 
erage 1.440). The butyric and caproic acids fully maintained their per¬ 
centage during the four months of the experiment, but the caprylic and 
capric acids decreased. 
As compared with the herd sample (Table II) the but3a*ic acid averaged 
higher by 0.183 per cent, the caproic acid higher by 0.529 per cent, the 
caprylic acid lower by 0.256 per cent, and the capric acid lower by 0.391 
per cent. 
The percentages of lauric acid were 5.806, 5,415, and 4.913 (average 
5-37^); of tlie myristic acid 20.682, 20.297, and 20.931 (average 20.637); 
of the palmitic acid 20.508, 22.257, and 19.103 (average 20.623); of the 
stearic acid 9.019, 8.707, and 10.729 (average 9.485); and of the oleic acid 
31.165, 30.828, and 31.868 (average 31.287). The lauric acid decreased 
with advancing lactation; otherwise there was no consistent change noted. 
As compared with the herd sample (Table II) the lauric acid was low 
by 1.517 per cent, the myristic acid low by 1.981 per cent, the palmitic 
acid high by 5.165 per cent, the stearic acid low by 1.899 per cent, and 
the oleic acid high by 0.142 per cent, a noticeable difference in propor¬ 
tion of constituent acids. 
ANALYSIS OF BUTTER FAT FROM HERD B 
Colantha II and Samantha III were considered as herd B. The cream 
was mixed and churned and 10 samples of butter fat, representing five 
feeding periods, were analyzed. The first sample in each period was 
considered indicative, but the second, taken after the same feeding had 
been continued two weeks longer, was regarded as a better criterion of 
the effect of the oils and fats fed and consequently for esterification. 
Fat samples B, and Bg were of similar character, differing somewhat 
in content of soluble fatty acids. As compared with A2, Bj contained 
practically the same amount of total, free, soluble, and insoluble fatty 
acids and of glycerol; but the neutralization number of the insoluble 
acids was slightly higher, 1.174 mgm. It again appears reasonable to 
assume that, if the feeding of oils and fats was wiftout influence, the 
composition of the butter fat of herd B should continue fully as uniform 
as that from herd A, thus permitting a direct comparison of the prelimi¬ 
nary Bg and subsequent feeding periods with possibly a slight allowance 
for advancing lactation. 
The soluble fatty acids in B4, from cows receiving coconut fat, decreased 
1.243 cent, as compared with the insoluble fatty acids increased 
1.249 per cent and their neutralization number 3.194 mgm., a decided 
change both in quantity and character of the insoluble acids. 
The total fatty acids in B^, from cows receiving peanut oil, increased 
0.226 per cent, and their neutralization number decreased 11.213 mgm.; 
the soluble fatty acids decreased 1.206 per cent, and their neutralization 
number, 20.055; th^ insoluble fatty; acids increased 1.432 per cent, and 
their neutralization number decreased 6.983; and the glycerol decreased 
0.548 per cent, indicating a notable gain in proportion of higher molecular 
weight acids in both groups. 
