446 



PRINCIPLES OF AGRICULTURAL CHEMISTRY 



second. The second ration should produce the same results in 

 two months that the first would give in five. In the latter case 

 there is not only a greater expenditure for food, but also twice as 

 long to feed and care for the animal. 



This may be put in another way. Suppose a steer 

 weighing 800 pounds is fed on 5 pounds cottonseed meal and 20 

 pounds cottonseed hulls per day. This ration would have a 

 productive value of 1.55. The animal would have a maintenance 

 requirement of 1.2, leaving 0.35 pound for fattening, which 

 would produce about 0.5 pound gain in live weight per day. Sup- 

 pose one pound corn meal is substituted for one pound cotton- 

 seed hulls. The ration would gain 0.17 pound in productive 

 value, which should cause a gain of about 0.25 pound in live 

 weight per day. An addition of 2 pounds corn meal would thus 

 double the gain in weight per day. 



Too heavy a fattening ration taxes the capacity of the animal, 

 and decreases the production of fat. The excess interferes with 

 the digestive processes and makes the fattening less successful. 

 Experiments have shown that an excessive ration does not pro- 

 duce as large gains as a ration adapted to the capacity of the 

 animal. The following are results of two series of experiments 

 by Morgan 1 on sheep, in which the quantity of protein was kept 

 constant, but the carbohydrates were increased. The effect of 

 the increase in the ration is to decrease the gain in weight. 



DIGESTIBLE NUTRIENTS FED PER 1,000 POUNDS LIVE WEIGHT. 



Quoted by Kellner, Die Ernahrung d. Landw. Niitzture, p. 414. 



