436 NUTRITION OF FARM ANIMALS 



protein (or, more exactly, the increase in the fat-free body) 

 considerably exceeds the gain of lean meat proper and with in- 

 creasing maturity this difference seems to become relatively 

 greater. 



512. Best age for fattening. While meat production in 

 the narrower sense of increase of protein tissue is confined to 

 the immature animal, the improvement of its quality by the 

 fattening process is an essential part of commercial meat pro- 

 duction. Fattening, however, may be effected at practically 

 any time in the life of the animal. Assuming that an animal 

 is to be in the hands of the same owner from birth until 

 slaughter, at what stage should the distinctively fattening 

 process as distinguished from growth be begun? 



It is evident that the beginning of the fattening process may 

 be delayed too long. To take the extreme case, it would be 

 obviously uneconomical first to grow an animal to full maturity 

 and then to add a fattening period. While there is no reason 

 to suppose that the amount of feed actually expended in the 

 production of a unit of fat would be materially greater than if the 

 fattening were conducted during the latter part of the growing 

 period, the expenditure for maintenance, care, interest, etc., 

 would be simply so much added to the cost of production. On 

 the other hand, heavy fattening rations, containing large amounts 

 of non-nitrogenous nutrients, even if they do not interfere with 

 the growth of young animals, are uneconomical, tending either 

 to overload the meat with fat or toward the accumulation of 

 cheap internal fat, and making the animal ripe for the butcher 

 before his capacity for producing lean meat has been properly 

 utilized. A limited market exists, of course, for fat lambs and 

 veals; but for the production of the world's meat supply it is 

 important to utilize the capacity for growth up to a point at 

 least approaching maturity. Too early fattening tends to 

 produce an animal which, even if not of inferior quality, must 

 be maintained in a fat condition until the growth of lean meat 

 has had an opportunity to overtake that of fat. Plainly the 

 beginning of the fattening should be so timed that it will be 

 completed by the time the rate of gain of lean meat ceases to be 

 profitable under the existing market conditions. 



The period in the life of the animal at which fattening should 

 begin, then, will depend upon its inherited capacity for growth, 



