100 



MAINTENANCE RATIONS OF FARM ANIMALS. 



to acid hydrolysis. The following table shows some of the more 

 recent results obtained by Abderhalden and by Osborne : 



Constituents of proteins — Abderhalden and Osborne. 



Constituents. 



Gliadin 



of 

 wheat. 1 



Gluten- 

 in of 



wheat. 1 



Zein 

 of 

 maize. 1 



Pha- 

 seolin of 

 white 

 bean. 1 



Casein. 2 



Egg 

 albu- 

 min. 2 



Serum 

 albu- 

 min of 

 horse 

 blood. 2 



Serum 

 globu- 

 lin of 

 horse 

 blood. 2 



Ox 

 mus- 

 cle. 3 



Edestin 



from 

 hemp. 4 



Glycocol 



P. ct. 



P. ct. 

 0.89 

 4. 65 



.24 

 5. 95 

 M. 23 

 1.97 



.91 

 23.42 



.74 

 4.25 



.02 

 1.92 

 1.76 

 4.72 

 4.01 

 ( 5 ) 



P. ct. 



P. ct. 

 0.55 

 1.80 



1.04 

 9. 56 

 2.77 

 3.25 

 5.24 

 14.54 

 .38 

 2.17 



P. ct. 

 0.00 

 . 90 



1.00 

 10. 50 

 3.10 

 3.20 

 1.20 

 11.00 

 .23 

 4.50 

 .06 

 5.80 

 2.59 

 4.84 

 1.95 

 1.50 



P. ct. 

 0.00 

 2. 10 



P. ct. 

 0.0 

 2. 7 



P. ct. 

 3.5 

 2. 2 



( 5 ) 

 18. 7 

 1 2.8 

 3.8 

 2.5 

 8.5 



P. Ct. 



2.06 

 3. 72 



.81 



11.65 

 5.82 

 3.15 

 4.51 



15.49 

 (?) 

 2.20 



P. ct. 

 3.80 

 3. 60 



( 5 ) 



20. 90 



8 1.70 

 2.40 

 4.50 



7 6.30 

 .33 

 2.10 

 .25 

 1.00 

 1.10 



11.70 



Alanin 



2.00 



.21 

 5. 61 

 7.06 

 2.35 

 .58 

 37.33 

 .13 

 1.20 

 .45 

 .00 

 .61 

 3.16 

 5.11 

 ( 8 ) 





Amino- valerianic 

 acid 









6. 10 

 2.25 

 4.40 

 1.50 

 9.10 



20. 

 i 1.0 

 3.1 

 3.1 

 7.7 

 .6 

 2.1 

 2.3 



Prolin 





Phenylalanin 





Aspartic acid 



Glutamic acid 



Serin 



"ih'.hi 



Tyrosin 





1.10 

 .20 



2.5 

 .7 



Cystin 





Lysin 



.00 

 .81 

 - 1.82 

 3.61 

 .00 



3.59 

 1.97 

 4.72 

 2.06 



( 5 ) 



7.59 

 1.76 

 7.47 

 1.07 



( 5 ) 



Histidin 









Arginin 









Ammonia 



1.63 







Tryptophan 



Total 



( 5 ) 



( 5 ) 



( 5 ) 



65.81 



59.66 



23.11 



53.64 



52.37 



28. 38 



42.6 



45.2 



67.30 









1 Osborne. The proteins of the wheat kernel, pp. 110, 113, and 118. 



2 Abderhalden. Lehrbuch der physiologischen Chemie. 



3 Osborne. The American Journal of Physiology, vol. 24, p. 437. 



4 Abderhalden. Loc. cit. 



5 Present. 



6 A prolin. 



7 A later determination by Osborne (American Journal of Physiology, vol. 15, p. 333), 

 confirmed by Abderhalden, gave 18.74 per cent. 



While many of the figures of the foregoing table can not lay claim to a high 

 degree of quantitative accuracy, it is, nevertheless, clear that the proportions 

 of the various atomic groupings in the protein molecule vary within wide 

 limits, while in some cases the most careful search has failed to show the 

 presence of certain constituents. Thus, glycocol and lysin were not found in 

 gliadin, nor lysin and tryptophan in zein, while ox muscle yielded a consider- 

 able percentage of lysin, a moderate amount of glycocol, and showed the pres- 

 ence of tryptophan. 



ABSENCE OF CERTAIN CONSTITUENTS. 



There is now a general agreement that in the process of digestion the pro- 

 teins of the feed undergo extensive cleavage and are to a large extent broken 

 down either into individual amino-acids or into comparatively simple peptid- 

 like compounds. These substances are resorbed by the intestinal epithelium 

 and the diverse proteins of the body are formed from them by synthetic proc- 

 esses, either in the intestinal wall or beyond. Such being the case, it has 

 seemed clear that, for example, the proteins of ox muscle containing 2.06 per 

 cent of glycocol and 7.59 per cent lysin could not be produced from gliadin. 

 which is lacking in both these groups, nor from zein, which lacks lysin and 

 tryptophan. 



The classic example of the effects of such a deficiency is, of course, gelatin, 

 which contains neither tyrosin, cystin, nor tryptophan. Bischoff and Voit 1 



1 Hermann's Ilandbuch dor Physiologie, vol. 6, pp. 122 and 395. 



