THE FATTENING OF MATURE ANIMALS 



367 



In the final period of an experiment by Weiske with lambs cited 

 in 'Chapter XI (487) the animals, when two years old, received an 

 exclusive hay ration from which they digested 1.22 Ib. of protein 

 per 1000 pounds live weight. While no material fattening was pos- 

 sible on such a ration, there was still a gain of protein nearly as great 

 per head as in earlier periods, thus rendering it probable that the pro- 

 tein supply was at least nearly sufficient for a moderate rate of 

 fattening. 



The foregoing results indicate that 1.5 Ib. of digestible protein 

 per day and 1000 pounds live weight is at least sufficient for 

 mature fattening sheep, while the experiments on cattle about to be 

 mentioned suggest that the amount might even be reduced consider- 

 ably below this limit. 



Cattle. In Kellner's respiration experiments upon fattening 

 cattle (443) , rations containing comparatively small amounts of protein 

 produced as satisfactory a rate of fattening as those richer in that 

 nutrient. Dividing the experiments into five groups according to 

 the amount of digestible crude protein consumed gives the following 

 averages : 



TABLE 76. INFLUENCE OF PROTEIN SUPPLY ON GAIN BY MATURE FAT- 

 TENING CATTLE 



The greater gains obtained in the experiments in which the larger 

 amounts of protein were fed are not to be ascribed to this fact but to 

 the greater consumption of total feed, since it has been shown that 

 protein is no more available than non-nitrogenous nutrients for fat 

 production. The point of the comparison is that rations containing 

 amounts of protein little if at all greater than the maintenance require- 

 ment gave relatively quite as large gains per unit of energy supplied 

 as did those containing three or four times as much protein. 



