HEIFERS DURING PREGNANCY AND SUBSEQUENTLY 93 



ferred. These include: (i) The maintenance of animals 

 for a comparatively long period without obtaining any 

 revenue from them in the form of progeny or of milk ; 

 and (2) failure to breed, that is, the loss or at least the 

 apparent loss of the power to reproduce. The answer 

 to the first objection lies in the fact that the value of 

 the performance of the breeding animal is to be meas- 

 ured not by the earliness of the period at which it begins 

 to produce so much as by the character of the produc- 

 tion during the whole period of productivity. The value 

 of the former is insignificant compared with the value 

 of the latter. The important consideration, therefore, is 

 to have animals that are to be retained in the herd come 

 into productivity at an age which will prove no handicap 

 with reference to their future usefulness. 



Experience has shown that when breeding is long 

 deferred conception is not so certain as at an earlier 

 period. For instance, the number of cases in which 

 animals fail to breed when required to drop calves at 

 three years old is greater than the number in which 

 they fail to breed when the aim is to have them drop 

 calves at two years old. The first is that the breeding 

 powers, like all the other powers that inhere in the 

 animal, are strengthened by use, and the second is that 

 females with which service is deferred to the later period 

 frequently become so fleshy that the generative function 

 becomes inactive. It has been argued in favor of early 

 conception that nature is unerring in her determinations, 

 and that nature would not make the ability to reproduce 

 possible at an age too early for reproduction to begin. 

 That is true where the processes of nature are left un- 

 disturbed. Wild animals do not become capable of 

 breeding at too early an age. But cattle are reared 

 under artificial conditions which are far from being the 

 same as those which nature furnishes unaided. Apply 

 to the human family generally the practice of reproduc- 



