444 NUTRITION OF FARM ANIMALS 



larger proportion of the higher priced cuts and a higher quality 

 of meat. They are all important factors in the economic pro- 

 duction of meat, but there is no evidence that their possession 

 renders an animal any more efficient as a converter of feed into 

 meat. 



520. Early maturity. The economic importance of a rapid 

 rate of growth and of the consequent early maturity has been 

 considered in previous paragraphs (504, 505). 



It is a matter of common experience that there exist marked 

 differences between individuals of the same species both as to 

 the weight finally attained by the mature animal and as to the 

 rate of growth at the same age. It is natural to interpret this 

 fact as indicating corresponding individual differences in the 

 rate of growth, especially of protein tissue, but the writer is 

 not aware of any recorded experiments bearing specifically on 

 this point. It is true that the quality of early maturity is 

 popularly attributed to the meat breeds, but as regards cattle 

 at least Henry 1 has shown that the data at hand fail to prove 

 that the beef breeds as such show a greater rate of gain in live 

 weight or a greater weight at maturity than do the dairy breeds, 

 although it is likewise true that other elements than simply 

 the weight enter into the economic conception of maturity. 

 If it is correct to ascribe the individual differences noted above 

 to variations in the rate of growth of protein tissue, it sug- 

 gests a field for investigation of much interest both to the 

 breeder and the feeder. 



3. FEEDING FOR MEAT PRODUCTION 



521. Feeding as related tojndividuality. The facts consid- 

 ered in the previous section relate to the capacity of the animal 

 as a mechanism for the conversion of vegetable products into 

 meat. They (and other less important ones) determine the 

 degree to which, from the commercial standpoint, the animal 

 is able to utilize the feed given it. Favorable modifications 

 of any of these factors are of advantage because they enable a 

 larger and more profitable production to be secured. 



Feeding stands in a somewhat different relation, in that its 

 purpose is to supply the material upon which the mechanism 



1 Feeds and Feeding, loth Ed., p. 329. 



