THE BREEDING OF HORSES 215 



condition of the generative organs should be avoided. The oper- 

 ator's nails should be short and clean, the hand and arm thor- 

 onglily washed and lubricated with mild soap suds or vaseline. 

 The utmost care must be exercised not to abrade or infect the 

 mucous surfaces in manipulation. The collection of the semen 

 is best made with a syringe which can be boiled and a flexible 

 nozzle is an advantage. The fluid is then transferred, one by one, 

 into as many one-ounce conical shaped gelatine capsules as there 

 are mares to breed, the syringe being immersed in water at 

 body temperature, in the interval between the filling and insert- 

 ing of each capsule. 



No special restraint is necessary, as a rule, but restive mares 

 may have a twitch applied to the nose, and possibly a side line to 

 hold up one foot. Heavy or stiff tails would be better tied to 

 one side or bandaged. 



Testing the Potency of a Stallion. — Recognizing the part the 

 male may play in sterility, it is important to test the semen from 

 time to time, not only to detect impotency, but to determine the 

 results of too heavy service, masturbation, overfeeding, emacia- 

 tion or any condition which may affect the vitality of the male 

 germ cells. A sample of semen is received in a clean container 

 at the conclusion of a service, and a few drops placed on a slide 

 or cover glass to be examined under a low power microscope. 

 Normally the spermatozoa or male sex cells will be seen actively 

 motile, forcing their way across the field by a vigorous lashing 

 of their tails. They are present in great numbers, 428,000 

 per cm.* Their motility is gradually lost under the influence 

 of drying, light, and high temperature. 



REVIEW 



1. Describe the forces involved in breeding. 



2. What is the relation of the parent to the ancestry on the one hand 



and the progeny on the other? 



3. Explain the greater breeding value of the pure-bred parent. What 



is the pedigree? 



4. What is meant by prepotency and upon what may it depend? 



5. What are the objections to cross-breeding and when is it justifiable? 



* Lewis, Okla. Exp. Station Bui. 93 and 96. 



