8 



Ration (c) was fed to group I after (b), and to group II after 

 ( a I, and the cows were also tried individually. In three trials it 

 had no effect on the volatile acids ; but the iodine number was 

 increased so sharply that the increase must have been partly due 

 to the food and not wholly to the advance of lactation. It was fed 

 to Chinchilla after (b) and to Duchess and Duchess, 2d, after (e). 

 These trials also showed the same action upon the iodine number, 

 and gave an increase in the volatile acids likewise, which will be 

 further mentioned. 



COTTON-SEED MEAL 



was fed in ration (e) to groups III and IV after (a), and the indi- 

 viduals of the groups Chinchilla, Duchess, and Duchess, 2d, were 

 compared at the same time. The iodine number was very much 

 depressed in each case and the volatile acids also, with the excep- 

 tion of Chinchilla. Now it may be noticed that the increase of 

 volatile acids after feeding gluten meal (c) was in each case pre- 

 ceded by the feeding of cotton-seed meal (e), or (e) and (b). 



THESE RESULTS ARE IN ACCORD 



with those given in Bulletin No. 13 and therefore our observa- 

 tions all show that corn meal had no effect on the volatile acids • 

 but loivered the iodine number \ gluten meal affected the volatile 

 acids only after they had been depressed by some other food, 

 when it raised them, while the iodine number was raised in every 

 case ; cotton-seed meal lowered both volatile acids and iodine 

 number. 



GREEN GRASS WAS COMPARED WITH HAY 



by feeding rations (g) and (h) after ration (b). 



It was tried upon only one cow, Duchess of Hanover. Ration 

 (g) was like ration (b), except that the hay of the latter was re- 

 placed by its equivalent of grass. This ration caused no appreci- 

 able variation in the butter-fat. Ration (h), which followed ration 

 (g), had a portion of its corn meal replaced by wheat-gluten meal, 

 a nearly pure albuminoid substance. The effect of this ration was 

 to increase the volatile acids slightly ; while the iodine number 

 was slightly decreased. Ration (j) contained no grain, consisting 

 wholly of pasture-grass. A study of the samples from three of 



