New York Agricultural Experiment Station. 499 



Transition period. From noon May 18 to morning May 23. 



During this period the wheat gluten was decreased ^ 

 lb. per day and the corn meal was increased by the 

 same amount, the purpose being to diminish the 

 amount of protein and to increase the proportion of 

 carbohydrates up to any probable requirements of 

 the animal for maintenance and milk production. 



Ration 4. From noon May 23 to morning May 31. 



Differed from No. 3 in that the wheat gluten was 

 withdrawn from the ration and 1| lbs. daily of corn 

 meal was added. 



Ration 5. From noon June 1 to morning June 20. 



Similar to No. 4 only one-third smaller. It was ex- 

 pected that this ration would be considerably below 

 the needs of the cow. 



Transition period. From noon June 20 to morning June 24. 

 i lb. wheat gluten added to No. 5 each day. 



Ration 2. From noon June 24 to morning July 30. 



During this period the food was the same as during 

 the two weeks succeeding April 26. 



The Methods of Sampling and Analysis. 



The rations were weighed out at several different times during 

 the course of the experiment, and each time this was done sam- 

 ples were taken of the various foods. The similarity in composi- 

 tion of these several portions indicates that the mixing and sam- 

 pling were thorough. 



The milk, urine and feces were taken directly to the laboratory 

 and immediately weighed and sampled, excepting that the night's 

 milk was kept in an ice box until morning when it was mixed 

 with the morning's milk and a sample was then drawn from the 

 mixture. The feces were thoroughly stirred and samples (4 lbs.) 

 of the fresh material were taken for drying and for the nitrogen 

 determination. The feces were dried over steam coils at a tem- 

 perature not exceeding 60° C. 



In general the methods of the A. O. A. C. were followed in the 

 analyses, the only exception being that petroleum ether was used 

 instead of sulphuric ether in extracting the fats from the foods 

 and feces. 



