10 



University of New Hampshire 



[Sta. Bull. 331 



From its beginning to the present time this research has been in 

 charge of E. G. Ritzman representing the Experiment Station. Until 

 his retirement in December, 1937, the station was fortunate in having 

 the consulting and advisor}' benefit of Dr. F. G. Benedict, without 

 which this work, both in its scope and fundamental character would 

 have been impossible. 



Aside from the purely physiological objectives, this research has 

 represented to a material degree pioneering in the improvement of 

 procedure and design and construction of apparatus, so that energy 

 transformations in livestock could be measured more rapidly and 

 more economically. As a result this laboratory has been able to 



FIGURE 5. TWO SIX-NIPPLED YEARLING RAMS FROM OUR FLOCK SENT TO THE 

 ROTHAMSTEAD EXPERIMENT STATION, ENGLAND, FOR BREEDING PURPOSES 



more than double the amount of work with a much smaller staff 

 than had been previously required, and the cost, which had been a 

 seriously limiting factor to the existance of research of this charac- 

 ter, has been reduced correspondingly. 



Thus during the past 21 years that this research has been in prog- 

 ress we have carried out over 1000 separate measurements of the 

 heat production and energy demands of farm livestock under condi- 

 tions comparing the effect of extremes in environmental condi- 

 tions such as temperature and seasonal variations in sunlight, of age 

 periods ranging from birth to maturity, of fasting and of the effect 

 of food itself varying from prolonged under-nourishment to heavy 

 fattening rations, of pregnancy and of lactation, and of the demands 

 for active work, such as walking, trotting, and the pulling of heavy 

 loads bv horses. 



