ANIMAL BREEDING 99 



without exercise for more than two or three weeks after birth_ 

 they are likely to get this disease, and some almost invariably 

 die. Sometimes whole litters die. Like results are likely to 

 occur with other animals, but, of course, death does not always 

 come in the same form. 



Environment or the influence of surrounding conditions 

 may also act more slowly and extend through several genera- 

 tions. Then it is said that the stock "runs out" and new 

 blood must be introduced. But this is caused by either one of 

 the three above-mentioned factors, namely, breeding, feeding 

 or environment. The animals may be kept under conditions 

 which are not favorable to improvement and then they go 

 back. Such conditions in time will reduce them in general 

 usefulness to a point at which they will no longer be able to 

 fulfill their purpose. 



In furnishing an environment for farm animals two main 

 points should be kept in mind. (1) The animals should be 

 kept under conditions that are as nearly normal or as to those 

 of nature as possible. (2) These natural conditions should be 

 modified to fit the improved rather than the wild animal. 



Acquired Characteristics. The characteristics infused into 

 animals by several generations of environment, feeding and 

 breeding become fixed and are transmitted to a greater or less 

 degree to the offspring. Thus, the man who uses the right 

 kind of a sire may get from 10 to 20 per cent, more gain 

 on his animals than he would if he used the wrong kind of a 

 sire. Furthermore, he may not himself be in position to 

 produce the right kind of a sire. 



The characteristics that animals acquire owing to environ- 

 ment, etc., may be either good or bad. On this account, 

 the author always makes it a practice to study first the en- 

 vironment under which the animals were developed, then the 

 feeding, then the type and conformation, and finally the breed- 

 ing or pedigree. In buying an animal on pedigree alone there 

 is only a rare chance of getting a good one. The above- 

 mentioned factors may all be on the wrong side with their 

 influence. As shown, previously, one-half of the offspring 

 are below the average and again the breeder frequently keeps 

 the best ones for his own use. 



