8 U. OF X. H. AGR. EXPERIMENT STATION [Bulletin 227 



One five-day fasting respiration experiment was also made with 

 each steer to study the decline in methane production. Much of this 

 work has been necessary for the best utilization of the data on fast- 

 ing which have been compiled for publication and which have now 

 gone to press. This publication, entitled "The Metabolism of the 

 Fasting Steer", will appear as Publication No. 377 of the monograph 

 series of the Carnegie Institution of Washington. 



The Station has had the good fortime to have the continued active 

 participation of F. G. Benedict of the Carnegie Institution on this 

 work, which has been under the local direction of E. G. Ritzman. 



DAIRY CATTLE 



Nutrition Studies with Dairy Cows — {Purnell Fund — in Cooperation 

 ivith the Carnegie Institution of Washington) 



In beginning this work with dairy cows it was deemed advisable by 

 Messrs. Benedict and Ritzman to start with a study of maintenance 

 requirements which have long been a subject of controversy. Since 

 the standards of maintenance feeding now in use vary materially, it 

 seems highly desirable to determine first by use of the respiration 

 chamber, the daily heat production of these cows when fed rations 

 based on maintenance determined by live-weight exjieriments. Two 

 kinds of feeding were used, namely, alfalfa hay and timothy hay with 

 linseed oil meal, both rations having previously served as a basis for 

 determination of maintenance requirements. 



The technique followed was much the same as with steers. The 

 animals were kept under constant conditions of feed and environ- 

 mental temperature for at least three weeks prior to a respiration 

 experiment and the same conditions were maintained through the 

 experiment except that feed was withheld during the last two days. 



As the mechanical device for separating the collection of urine and 

 feces from cows was not perfected to operate with a sufficient degree 

 of accuracy until toward spring, few samples of urine and feces were 

 obtained for separate analysis. This work will be repeated along much 

 the same lines during the coming year. 



A Physiological Study of Dairy Cows — [Purnell Fund) 



The, data secured during the year by J. M. Fuller indicate that the 

 respiration rates of cows under normal herd conditions may vary from 

 12 to 58 per minute and that pulse rates of cows under normal herd 

 conditions may vary from 52 to 88 per minute. A three-days' contin- 

 uous observation of 38 cows showed on the average approximately 50% 

 of the time was spent standing and 50% lying. Variations ranged from 

 34,8% standing to 63.35% standing. 



A three-day observation, made on water consumption by cows in 

 the University herd, showed a minimum consumed by any one cow 

 through a 24-hour period of 18 pounds and a maximum of about 

 233% pounds. 



The amount of urination and defectation during a three day period 

 was noted. The maximum number of urinations and defectations ran 

 as high as 20 per day with some cows. 



