11)04.] PUBLIC DOCUMKNT — No. 33. 61 



The results indicate that tliorc was no inirtieukr dillerence 

 in the percentage of fat left in the skim milk or buttermilk 

 produced by the two herds, excepting in case of the butter- 

 milk obtiiined from the butter produced by Herd II. in the 

 third period, when .20 per cent, more fat was found than in 

 that produced by Herd I. As the period of lactation became 

 advancegi, more fat was left in the skim milk produced by 

 both herds. This, however,- is a well-established fact with 

 cream raised by the gravity process. 



Conclusions. — The fact must not be overlooked that this 

 experiment, on wliich the following conclusions are based, 

 extended over a period of six months, with periods varying 

 from tliree to seven weeks in length ; the period proper w^as 

 always preceded by a preliminary period of two weeks. 



1. The immediate effect of the addition of .6 pounds of 

 corn oil to the corn gluten meal ration was to increase the 

 fat percentage in the milk .23 of 1 per cent. (5.17 to 5.40) ; 

 at the end of two wrecks the effect of the corn oil had disap- 

 peared, and the milk had returned to its normal fat content. 



2. The removal of the corn oil from the daily ration caused 

 a sudden drop of .54 per cent, in the fat (4.97 to 4.43), but 

 after the first w^eek the normal fat per cent, was again present. 



3. Corn oil appeared to have depressed the nitrogen per- 

 centage in the milk by .034 per cent. (.610 to .57(3) ; the 

 nitrogen gradually returned to its normal percentage after 

 the feeding of the corn oil had ceased. 



4. It is not considered practicable to feed large amounts 

 of oil to cows, it having a tendency to derange the digestive 

 and milk-secreting organs. 



5. Corn meal was without effect on the composition of the 

 milk. 



fi. There was but little change in the composition oH the 

 milk i)roduced by Herd I. for a period of six months, during 

 which time the herd received the same or so-called standard 

 ration ; a gradual increase in the percentage of solids not fat 

 only was noted. 



7. Corn gluten meal and corn meal were without notice- 

 able influences on the chemical composition of the butter fat. 



8. The addition of corn oil to the corn gluten meal ration 

 caused a depression of 10 points in the saponification equiva- 



