LECTURE LXXXIV. 



INFLUENCES OF CROSS-BREEDING AND GRADING. 



By the term cross-breeding, in the strictest sense, we mean 

 the pairing of animals of two distinct breeds. In this sense 

 it may be considered to be the very opposite of in-and-in- 

 breeding. It is the mating of animals which are in no wise 

 related. 



Unfortunately the terms "cross-breeding," "crossing," "out- 

 breeding" and "making a cross" are very often misused and 

 interchanged so as to mean the mixture of blood of different 

 families of the same breed. For example, in the Shorthorn 

 breed of cattle we have several distinct families, such as the 

 Bates, the Booth and the Cruickshank. A man breeding the 

 Bates family might for some reason or other desire to use a 

 Booth bull. This would be termed "out-breeding" or an "out 

 cross," because it belonged to another family. Strictly speak- 

 ing, however, by cross-breeding we mean when animals of two 

 distinct breeds are used, such as the Shorthorn and the Gal- 

 loway, the Berkshire and Yorkshire, the Shropshire and Cots- 

 wold, or the Clyde and Shire. 



This method of breeding has been practiced extensively on 

 all classes of stock. It is still used in all sections of the 

 country more or less indiscriminately in most cases. For 

 many years it was used most extensively with sheep. The 

 Leicester and the Southdown were both used very extensively 

 for this purpose. In more recent years the Shropshire has 

 been used in many sections of this country for crossing pur- 

 poses. 



In the central west the crossing of the different breeds of 

 swine has been very commonly practiced. Several of the 

 newer and larger breeds have been crossed with the Poland 

 China with the hope of increasing their size and the size of 

 the litter. 



That the crossing of breeds has been beneficial in the 

 building up and improving many ouf breeds of stock cannot 

 be questioned. Practically all of our present improved breeds 



