EXPERIMENT STATION BULLETINS. 175 



coarser staples of wool always causes more or less crossing of coarse 

 wools upon fine wools or the reverse, as the case may be. No breeder 

 can make such radical changes as these, frequently, for every time he 

 alters his breeding operations so radically in trying to meet market 

 fluctuations, he introduces factors leading to the final deterioration 

 of his breeding stocks. It is much safer to choose some definite line 

 of production, and stand by that through the temporary ups and downs 

 of the market; the men who have done this have made a success of 

 animal breeding. It would not be sensible to say that no changes 

 should be made in one's breeding operations; if a man is sure he has 

 made a mistake, the only rational thing to do is to make a change, but 

 these should not be made often, as they are usually attended by some 

 loss. The progeny from some first crosses have shown highly desirable 

 results and while cross-breeding is more justifiable in the production 

 of market animals, it cannot be employed continuously in the produc- 

 tion of breeding stocks. From the breeders standpoint, each succeeding 

 cross becomes less and less satifactory. Cross-breeding is more justifi- 

 able among those classes of animals such as swine, which reproduce 

 quickly and abundantly, and mature early, for in such cases it is easily 

 possible to return to the original types for breeding animals. While 

 we must admit that cross-breeding has rendered valuable service, in 

 the form of single out crosses, in the formation of new breeds and 

 types, still, it should not be practiced among cattle on the ordinary 

 farm, for three reasons, viz.: (1) It would tend to destroy the identity 

 of breeds; (2) The results are in many cases uncertain, and (3) It 

 might render pure bred females lefes capable of breeding true to type. 



IN-AND-IN BREEDING. 



Because of the fact that the several terms used in connection with 

 the breeding of variously related animals are not always properly used, 

 or understood, it may be well to define them. (1) In-and-in breeding 

 implies the mating of animals closely related, for a number of succes- 

 sive generations; it includes close relationships and continuous repeti- 

 tion. (2) In-breeding implies the mating of related animals in a single 

 instance, or at intervals among the genersitions, without much regard 

 for the closeness of the relationship. (3) Close breeding merely implies 

 that closeness of relationship existed between the animals mated. (4) 

 Line breeding implies the breeding of animals within the members of 

 one family, or one or more related families. It is virtually a continua- 

 tion of in-and-in breeding, the relationships being less close. 



It is astonishing the extent to which in-and-in breeding and in- 

 breeding are allowed among the common stocks of the country, and 

 this too, by some persons who realize fully the seriousness of the 

 practice. It arises, of course, from the selection of sires from among 

 the offspring of the herd; in some cases, it may be due to a lack of 

 means to make a suitable purchase, but in general, it is due to careless- 

 ness or indifference. When in-and-in breeding is carried too far the 

 following evils are likely to result, viz, : loss of size, delicacy of consti- 

 tution, impaired reproductive powers, and in fact general deteriora- 

 tion. 



