THE EFFECT OF CHANGE OF TEMPEPvATURE 

 ON THE BASAL METABOLISM OF SWINE. 



By J. W. CAPSTICK, O.B.E., M.A., 



Felloiv of Trinitij College, 



AND 



T. B. WOOD, C.B.E., M.A., F.R.S., 



Drapers Professor of Agriculture. 



{From the Animal Nutrition Institute, School of 

 Agriculture, Cambridge.) 



Introduction. 

 It has long been generally accepted that an animal requires more food 

 in cold weather than in hot weather, that, in fact and within certain 

 limits, an animal's food requirement increases as the temperature falls. 

 The number of precise measurements however of the effect of change of 

 temperature on food requirement is very small, and it was with the 

 object of extending the knowledge of this important subject that the 

 following investigation was undertaken. 



The writers' attention was directed to the subject by a paper by 

 Armsby and Fries on " Net Energy Values and Starch Values " which 

 appeared in this Journal in 1919'. 



In this paper Armsby and Fries point out that their Net Energy 

 and Kellner's Starch Equivalents really measure the same thing, namely 

 the amount of energy in feeding stuffs which is available to the animal 

 for physiological purposes. They claim further however that this net 

 energy only is available for maintenance, and that any excess of energy 

 above this amount is converted at once into heat ivhich is of no value to 

 the animal. 



The point will perhaps be made clearer by a concrete instance, and 

 since figures on the subject are lacking in the case of swine, it may be 

 permissible to supply them for a steer. 



Armsby states that the basal metabolism of a 1,000 lb. steer is about 

 six therms or 6,000 calories per day. Most European authorities agree 

 that 14 lbs. of average meadow hay supplies a maintenance ration for a 



' 1 This .Journal, 9, 182. 



18—2 



