Infiuetice of Feed on the Animal Body. 



93 



123. Composition of carcass. — The data of the composition of 

 the dressed carcass are given in the following table, these being 

 divided into groups according to the feeding of the steers : 



Percentage composition of dressed carcass, fresh substance — Maine 



Station. 



Protein 



i-rich food Z^**^""^' ^^'11'^ 1^°®- 



1 ncn rooa | g^^^. ^^ ^^^ 27 mos. 



Protein-poor food I g^^^^r 3, fed 27 mos. 



^ \ Steer 4, fed 17 mos. 



Water. 



59.02 

 51.91 



52.16 

 56.30 



Protein. 



17.89 

 16.93 



17.10 



17.82 



Fat. 



18.53 

 25.86 



25.32 



20.27 



Ash. 



4.56 

 5.30 



5.42 

 5.61 



Let ns first study the carcasses of the steers fed for 17 months. 

 That of the steer getting the protein-rich ration contained 2.7 

 per cent, more water, the same amount of protein, and nearly 2 

 per cent, less fat than the other. This is in line with other work 

 in showing that one of the results of feeding much protein to 

 growing animals is a carcass containing more water. For the 

 steers carried through 27 mouths of feeding there is practically 

 no difference in the composition of the carcasses. 



124. Conclusion. — Reviewing this experiment we are led to con- 

 clude that rations rich in protein are more conducive to rapid 

 growth and finer general appearance of the animal when young, 

 than rations rich in carbohydrates apd rather poor in protein. It 

 appears that when the protein-poor ration contains enough nitro- 

 gen and ash to supply the actual demands of the body, the animal 

 carefully conserves them, being enabled thereby to fulfill the laws 

 of its nature as to growth. No doubt if the steers getting the 

 least protein had been supplied with less protein and ash than 

 nature requires for good body-building, they would plainly have 

 shown it by an abnormal development; but, fortunately, such con- 

 ditions were not laid down in this experiment This experiment 

 and its teachings should be compared with the feeding trials with 

 pigs by Sanborn, the writer and others, reported in the first part 

 of the chapter, where strongly one-sided rations were fed. 



