ANIMAL PRODUCTION. ' 967 



An excess of protein leads to a partial use of it to replace carbohydrates as 

 a source of energy. In such cases the nutritive value is relatively less than 

 when smaller amounts are supplied. 



Problems of growth and length of life from, the standpoint of energetics, 

 M. RuBNtR {Aicli. Hyy., 66 il'JOS), .Vo. 1-2, ///>. l.il-20S, chart. 'i 2; Sitzber. K. 

 Prciis.s. Akfifl. Wiss., JOGS, II, pp. J2-.}7). — The author discusses rate of growth 

 and duration of life of man and other mammals from the standixjint of ener- 

 getics. With respect both to the amount of protein and energy required during 

 the nursing period to double the body weight, man forms an exception to the 

 other mammals included in the author's discussion in that on a uniform basis 

 of comparison he rejuires smaller quantities of protein and about six times as 

 much energy. According to the author's calculations, domestic mammals require 

 on an average 4,S0S calories for building a kilogi-am of body material. 



A comparison is also made between man and other mammals with respect to 

 the proportion of energy sui)plie<l during the nursing period, which is retained 

 in the body. In this respect also man differs from the ordinary domestic ani- 

 mals, since he retains only 5.2 per cent of the net energy supplied in comparison 

 with 34.3 in the case of domestic animals. This value is called by the author 

 •• quotient of growth." He estimates further that in domestic animals the 

 ratio of food supply to maintenance is 202 to 100 and in man 120 to 100. so that 

 in the case of domestic animals 09 per cent of the material supplied is retained 

 in comparison with 0.2 per cent in the case of man. 



According to the author's summary, the time repiired by the young animal 

 for doubling the body weight is inversely proportional to the intensity of metab- 

 olism, and therefore the shorter the period of growth the greater the metabo- 

 lism of energy. The intensity of energy metabolism is a function of surface 

 area and therefore small animals show the more rapid growth. 



In his di.scussiou of the duration of life the author estimates that in the 

 domestic animals each kilogram of body weight after growth is complete*] 

 requires practically the same (piantiry of euergj-. Man forms an exception to 

 this rule, in that he reipiires about four times as much as the other m.nnmals. 

 It follow.s. therefore, that man retiuires a greater proiwrtional energy supply 

 than other mammals. 



The problem of duration of life and its relation to growth and nutrition, 

 M. liUBXKK t Du.f I'rohlcin ilcr Lcbt n-silaucr iiiul .'^riiie Beziihungcn zu Wachstum 

 und Enuihning. Munich, 190S. pp. VIII+20S; rev. in Biochcm. VcntbL. 7 ( 1908). 

 .Yo. J 0-16, pp. 593, o9.'i). — A fuller discussion of problems considered in the 

 article noted above. 



ANIMAL PRODUCTION. 



[Experiments in animal production], W. H. Jordan and W. P. Wheeleb 

 (.Vc/r York .State Sta. lipt. I'.ur,. pt. J. pp. 66-109. plx. 2).— A summary of ,vork 

 done at this station during the first 25 years of its existence. 



Some of the more important results obtained are as follows: Com cut on 

 September 20 contained a large increase in cjirbohydrate material over that cut 

 September 11. From a number of experiments it was concludeil that the 

 • Jernian fee<ling standard called for a larger protein ration than is necessjiry. 

 In T.K»l it was demoustratetl that the quality of the milk is determined by the 

 individuality of the animal and not by the quality of the ftHil. It was also 

 found that it was not possible to influence the amount of water in cow's milk 

 througli either the drinking water or watery food. Wet brewers* grains proved 

 to be a valuable feetl when given in the right proixtrtions. Carbohydrates in 

 the feed were found to furnish the raw material for the production of a large 



