ON THE PRODUCTION OF LEAN MEAT IN 

 MATURE ANIMALS. 



It lias been pretty conclusively shown in experiments by 

 Henry,* Sanborn, t and at this Station,]; that the relation between 

 the lean and fat in the carcass of yoinig animals can be varied 

 in quite wide liniits by varying the relation between the nitroge- 

 nous and carbonaceous matters in the ration fed. But it has been 

 stoutly maintained that, in the mature animal or the animal whose 

 nuiscles have once been formed, it is practically impossible to 

 increase, either relativelj^ or absolutely, the amount of muscle or 

 lean meat. It was to throw some light on this question that the 

 experiment recorded below was determined upon. 



At the outset numerous difficulties confronted us, chief among 

 them being the necessity of relj'iug wholly on comparison between 

 individuals, for the composition of an animal's body manifestly 

 cannot be determined at two different periods of its life. 



Another obstacle in work of this kind is the difficult}^ of 

 completel}' separating the fat and lean of the carcass by mechan- 

 ical means, particularly when Liiere is any considerable amount of 

 what maybe termed " internuiscular fat" and connective tissue. 



After a careful consideration of all the difficulties involved, it 

 was finally determined to make a preliminary trial upon the fol- 

 lowing basis : Two mature animals in poor condition, as nearly 

 alike as may be, and if possible of near blood relationship, to be 

 selected. One of these to be slaughtered, the carcass rendered 

 and the nitrogenous matter and fat determined in the products 

 by chemical analysis. The other to be fed with a ration calcu- 

 lated to produce muscle or lean meat for a sufficient length of 

 time and then treated as the first. 



After some search, two animals fairly satisfactory were secured 

 in two grade Yorkshire sows, three and four years old, one the 



* Fourth Annual Report of the Agricultural Experiment Station of Wisconsin, p. 83, and 

 Fifth do., p 92. f Bulletins, Nos. 10, 14, 19, and 27, of the Missouri Agricultural College 

 Karji. X B lUetin, No. II, Cornell University Agricultural E.^cperinient Station. 



