586 



GENERAL PRINCIPLES OK BREEDING. 



brought into contact with the stronger, in the propagation of the 

 species, the offspring will bear the stamp of improvement, and not 

 of deterioration. In this way the commonest animal, continuously 

 bred to a superior strain of blood in the male, will in a few genera- 

 tions have acquired nearly all the physical excellences towards which 

 it has been bred up, except in regard to the transmission to off- 

 spring, which is never so strong as in the animal of pure blood of 

 its species. 



GENERAL, PRINCIPLES OF BREEDING. 



Conditions Required in the Parent Animals The 



breeders of live-stock cannot be too particular as to the condition of 

 the animals from which he desires issue, for their fertility will de- 

 pend upon various causes, and is susceptible to influences of even 

 trivial character. The previous course of the life of the animal will 

 frequently affect its power of reproduction, and especially when any 

 important end may depend, it is incumbent upon the breeder to as- 

 certain what this has been. When the Sp.'-nish Merino was first in- 

 troduced into England, there were numero is occurrences of barren- 

 ness of the ewes, and those which dropped lambs were often defi 

 cient in milk supply; these mishaps have been attributed to the 

 change in the sheep's mode of living, being relieved in the rich 

 pastures of England of the necessity for exertion under which they 

 lived in the mountainous districts of Spain. Again, the breeder 

 must look to the feeding which has been given his animals, because 

 in animals which have had the nutritive powers developed and sus- 

 tained to the proper degree, the greatest fertility may be expected. 



Influence of Feeding- upon Fertility It is of course 

 desirable to realize the largest production possible from stock. The 

 ewe which will drop twins, provided they be healthy, is in the 

 natural course of things more valuable than that which produces 

 but a single lamb. Scientific men have noted the fact that feeding 

 upon rich grasses will induce the dropping of twins by one ewe in 

 three, while in localities where there is not the same opportunity for 

 nourishment, not one ewe in twenty will do so. Dependence or fer- 

 tility upon food is also noted in the larger animals. As stated 

 by Mills, in his " Treatise on Food," " Mares which have been 

 brought up in the stable, on dry food, do not breed at first; some 

 time is required to accustom them to their new aliment." 



Excessive Fat Disqualifies a Breeding Animal 

 The greatest development of nutrition will have a tendency to im- 

 pair the vitality of the generative organs, for as Carpenter, in his 

 " Comparative Physiology," says, " There is a certain degree of an- 

 tagonism between the nutritive and generative functions, the power 

 of the one being executed at the expense of the other," and this ren- 

 ders it necessary for the breeder to draw closely the line of division 



