May, 1937] Agricultural Research in N. H., 1936 15 



energy as provided by some of the feeding standards now in common 

 use. This study by E. G. Ritzman and K. S. Morrow in coopera- 

 tion with F. G. Benedict of the Carnegie Institution, fomis the begin- 

 ning of an investigation on the adequacy of present standards for feed- 

 ing lactating cows. The cows used in this initial step were two large 

 framed Holsteins supplied by the dairy herd and the rations fed were 

 calculated on the basis of the Morrison standards. 



The result, which represents only a stage well advanced in the period 

 of lactation, cannot at present be assumed to apply to the entire pe- 

 riod. However, several significant facts may be reported at this time. 



In all five experiments, computed by accepted standards, there oc- 

 curred a minus balance in energy. An outstanding feature also appear- 

 ed in the extraordinary low utilization of the digestible crude protein 

 (as indicated by the high nitrogen content of the urine) in three out 

 five cases. There is strong evidence to indicate that the high nitrogen 

 content of the urine was partly the result of a katabolism of body pro- 

 tein to meet the energy deficiency in the ration. 



The general picture so far suggests the tendency to underfeed in en- 

 ergy and possibly to supply an excess of protein for cows whose inher- 

 ited tendency to secrete milk has definite limits. (Purnell Fund) 



Nutrition of Horse, Pig and Goat 



Measurements of the heat production of a Percheron stallion and of 

 a Thoroughbred stallion carried out during the year by E. G. Ritzman 

 in cooperation with F. G. Benedict, indicate a much higher basal me- 

 tabolism per unit of size in the more active racing type. 



Four basal metabolism experiments were carried out on one adult 

 Chester White boar weighing 235 Kilos, and on one adult Chester 

 White sow weighing 113 Kilos. The result, expressed on a basis of 

 heat loss per square meter surface area (using the formula lO.W^/^) 

 shows 980 calories for the sow which practically equals previous results 

 obtained on two Berkshire sows. The Chester White boar, on the other 

 hand, shows a basal heat production of 1600 calories per square meter 

 of surface area. Whether this represents entirely a difference of sex 

 seems improbable. 



Experiments were also carried out with goats and with sheep to 

 study the zone of thermic neutrality of these species, their relative re- 

 actions to changes in environmental temperature, and the effect of their 

 body covering on heat loss and heat production. These studies fomi 

 the beginning of a research on the validity of the theory that basal 

 heat production is determined by rate of heat loss and that all warm- 

 blooded animals regardless of species give off heat in direct proportion 

 to their surface areas and at an essentially constant rate. {Adams 

 Fund) 



Sheep Breeding 



Some further progress has been made during the year by E. G. Ritz- 

 man toward establishing a flock of sheep with the functional capacity 

 of four nipples ; 75 per cent of the ewe flock now have from three to five 

 functional nipples. This has been due to the addition of fifteen yearl- 



