12 N. H. Agr. Experiment Station [Bulletin 262 



by Armsby for these same feed-stuffs, report E. G. Ritzman and F. G. 

 Benedict. Since the possibility of measuring the net energy value of 

 individual feed-stuffs has recently been challenged, it will be necessary 

 to repeat much of this work as a matter of routine before the results can 

 be definitely accepted. 



In connection with the digestion balances a material progress has 

 been made by further improvement of the apparatus for the separate 

 collection of feces and urine from cows. Tests with artificial and with 

 natural urines have shown that the loss of nitrogen during a 24-hour 

 period can now be held under two per cent. (Purnell Fund) 

 The Metabolism of the Horse 



Metabolism measurements were made on three horses during the 

 year. Except for the work of Zuntz (1894) using a tracheal canula. 

 these are, so far as we are aware, the only direct metabolism measure- 

 ments carried out on this species. 



The fasting metabolism of the three animals while standing was 

 respectively 2,669, 2,206, and 2,000 calories per square meter of body 

 surface, giving an average of 2.292 calories. With a deduction of 25 

 per cent, for the effort of standing we have a basal metabolism of 1,719 

 calories, which indicates a materially higher basal requirement than 

 that of any other farm live stock and approximately double that of 

 man. The high metabolism characteristic of the horse is that of a 

 tensely nervous animal that does not easily lay on flesh and represents 

 a high degree of metabolic activity which is in full keeping with its 

 muscular power and the capability of almost explosive activity. 



A study of the changes in the respiratory quotient during fast in- 

 dicated that the two horses which subsisted on pasture up to the ex- 

 periment had exhausted their stored carbohydrate (glycogen) in about 

 48 hours, but the horse which was fairly heavily grain fed did not 

 exhaust his stored carbohydrates until about 100 hours after the last 

 food had been consumed. This large carbohydrate reserve which the 

 horse can store up explains his well deserved reputation for muscular 

 endurance. (Miscellaneous Income) 

 The Effect of Castration on Energy Metabolism 



Metabolism measurements made on both sheep and a pig before and 

 after castration indicate a lowering of the maintenance requirement 

 and thus a greater efficiency in flesh storage following the operation. 

 (Miscellaneous Income) 



Food Wastes Studied 



How far modern eating practices have strayed from the gospel of 

 the "clean plate" is shown in the study of edible food wastes com- 

 pleted by A. Gertrude Fa it in cooperation with Francis G. Benedict, 

 director of the Nutrition Laboratory of the Carnegie Institution of 

 Washington. It was found that students at college fraternity and 

 sorority houses sent back uneaten an average of 3 to 21 per cent, of 

 the calories served, and as high a percentage of the protein. The 

 principal reason, aside from personal likes and dislikes, is found in 

 their consumption between meals of extra foods— chocolate bars, pea- 



