54 HATCH EXPERIMENT STATION. [Jan. 



period, and did not again enter the experiment ; it is doubt- 

 ful, however, if her loss in any way aflected the composition 

 of the fat. 



In the third period Herd H. was still receiving a trifle 

 over 2 pounds of gluten meal daily, so that the ration was 

 essentially the same as in the second period, excepting for 

 the addition of .(5 pound of corn oil. It is in this period 

 that a noticeable modification of the butter fat took place 

 with Herd II., while the character of the fat produced by 

 Herd I. remained constant. The difterence consisted in the 

 decrease of the saponification equivalent by 10 points, a 

 decrease of the Reichcrt-Meissl number of 3i points, and an 

 increase in the iodine number of a trifle over 9 points. The 

 melting point of the fat, on the other hand, showed no marked 

 chano^e. Similar conditions were noted when cotton-seed 

 and linseed oils were fed,^ excepting that the two latter oils 

 also raised the melting point of the fat. 



In the fourth or corn meal period, when the rations of 

 both herds were similar, excepting that corn meal took the 

 place of ground oats with Herd II., the butter fat produced 

 by the latter herd returned to its normal condition, e.g., 

 similar to that produced in the first and second periods, and 

 closely resembling the fat produced by Herd I. during all 

 four periods. 



The only noticeable change in the fat of Herd I during the 

 entire experiment, ^ extending from October 20 through April 

 19, — a period of six months, — consisted in the slight gradual 

 decline in the Reichert-Mcissl number, due to advancing lac- 

 tation. It is interesting to observe the uniformity in the 

 character of butter fat produced by a herd of five cows hav- 

 ing the same feed during such a long period of time. 



The Ojnnion of Experts on the Character of the Butter, — 

 Two lots of cream from each herd, raised by the Cooley 

 process, were ripened and made into butter each week. The 

 ripening process generally lasted twenty-foiu* hours, and 

 some commercial starter was employed. The full details of 



* Thirteenth and fourteenth reports of this station, pp. 110, 165. 

 ^ Excepting the temporary depression in tlio iodine number in the second 

 period already referred to. 



