ILLINOIS DAIRYMEN'S ASSOCIATION. 201 



It is the belief of many of our best authorities that where 

 in-breeding or inter-breeding is practiced, which relates to a 

 single act of mating together animals which possess from fifty 

 to one hundred per cent of the same blood, chances are perhaps 

 equal for good or bad results. It is probably true, however, that 

 in the hands of the inexperienced stockmen the chances lor bad 

 results are perhaps considerably greater. Where animals of dif- 

 ferent generations, related within the degree of second cousins,, 

 are mated twice or more times in succession, which is stritctly in- 

 and-in-breeding, ht eprogeny is quite sure to be weakened in a 

 more or less marked degree by some o fthe evils accompanying 

 close breeding. 



Line-breeding is a popular system of breeding practiced by 

 many of our best breeders of today. It is somewhat difficult to 

 know just what the term implys, for the reason that as it is prac- 

 ticed by some men it is the purest form of in-and-in-breeding. 

 On the other hand the practice refers to mating animals belong- 

 ing to a certain family or perhaps to several families, which are 

 not so closely related as to cause any danger of evil results. The 

 latter practice is in accordance with the original idea which was 

 adopted by men who realized the evils of in-and-in-breeding. 

 Wisely and judiciously practiced, it tends to preserve a given 

 type and a performance which could not be so readily assured by 

 natural or ordinary breeding. Animals to be mated are carefully 

 and judiciously selected in every instance, and rather than take 

 too great chances of getting disastrous results by uniting blood 

 too closely related an out-cross will be made by using the blood of 

 some other family which the breeder has faith will nick well 

 with what he has succeeded in producing and is trying to pre- 

 serve. 



There are wonderful opportunities for the painstaking intel- 

 ligent man to achieve success and profit out of breeding opera- 

 tions. Close breeding in one form or another is one of the means 

 to be used in reaching such an end, but it is not the end itself 

 and cannot be generally recommended for this reason. There 

 are many instances where it will only prove a detriment rather 



