AS Report’ OF DEPARTMENT OF ANIMAL HUSBANDRY OF THE 
The next table summarizes the results of the entire periods 
during which exact observations were made, and expresses 
numerically the necessary conclusions from these investigations 
as to the formation of milk fat. 
RELATION OF MILK FAT TO Foop FAT AND PROTEIN. 
Fat not 
accounte 
Fat - Theoret- ed for Gain in 
Days of digested icalfat Fatin from weight 
expt. from from miik. foodfat of cow.* 
food. protein. and pro- 
tein. 
Lbs. Lbs. Lbs. Lbs. Lbs. 
Grade Jersey, fat-poor ration. 59 3.3 “lta 2836s 33. 
Cow 12, fat-poor ration....... 74 4.8 39:2 88 39 15 
Cow 2, normal herd ration.... Sat 2 2 6h Aiea eee — 
Cow 10, fat-rich ration..... aes 42” So. “1853 40.0° —-ove 18 
*Based upon average of ten days weighings. 
+ From Bul. 132, N. Y. Agl. Expt. Station. 
Some of the figures given are based upon assumptions for 
which there is little or no justification, but which certainly safe- 
guard drawing unwarranted conclusions as to the possible pro- 
duction of milk fat from carbohydrates. 
It is assumed that the digested food fat (ether extract) may 
be the source of an equivalent quantity of milk fat, but when 
we consider that ether extract is not wholly fat or oil, and that 
the glycerides of milk differ widely in kinds and proportions 
from the fatty compounds of the plant, we see how unwarranted 
such an assumption is. Again, the fat factor of protein is taken 
as 51.4, this being the maximum proportion based upon a theo- 
retical rearrangement of atoms, of the actual accomplishment 
of which we have no assurance. For these reasons the excess 
of milk fat as given, over and above that possibly derived from 
the food protein and fats, is quite probably considerably more 
than is stated. But even as the figures stand they are certainly 
convincing. It is not possible to avoid the conclusion that car- 
bohydrates serve as at least a partial source of the milk fat. 
With all four cows the ether extract was insufficient for sup- 
plying the milk fat to the extent of the following daily quan- 
tities, even allowing the absurd assumption that ether extract 
is all convertible into milk fat. 
Grade Jersey, fat-poor ration......... Cul devte Pe ae -60 lbs. 
Car12, fat-poor ration .7.7... 22 oe eee. ~ ©1506clbs, - 
Cow’ 2, Dorma! “herd “ration. .c..20.ecavcae pe ine ie -96 lbs. 
Cow 410, *faC-Peh raion 6 oa eee ee eee .30 lbs. 
