462 MANAGEMENT AND FEEDING OF SHEEP 



and less costly. To cover this question fully would mean 

 going into all the details of feeding. It can only be said, 

 further, at this time that if the food is to prove an effec- 

 tive means of improving flocks, it should be given so as 

 to best meet the needs of the individual sheep under all 

 the conditions of development and maintenance to which 

 it may be subjected, and it should be given, as far as may 

 be practicable, to maintain as much of equilibrium in con- 

 dition as may be attainable, otherwise the character of 

 the fleece will suffer. 



That the difference, to some extent at least, in the 

 food requisites for different breeds must be given some 

 recognition, will be apparent from the influence that food 

 has exercised in the evolution of the various breeds. 

 Where the food furnished differs materially from that 

 given under the conditions of environment that evolved 

 the breed, modifications will follow. These will be ad- 

 verse should the food supplies be lower than breed char- 

 acteristics call for to sustain them in equilibrium ; and 

 they will effect improvement in some respects if higher 

 than the breed characteristics have previously called for. 

 Thus it is that heavy breeds of sheep retrograde if put on 

 rations that will maintain equilibrium in the small breeds, 

 and thus it is that the latter improve in some respects 

 when the food is an improvement on the food consumed 

 while the breed was being evolved. 



The food fed should meet the needs of the sheep as 

 modified by breeding. Suppose a large sheep is crossed 

 upon a small one, the size of the progeny will be in- 

 creased as compared with the size of the dams which pro- 

 duced it. This will mean that food supplies that may 

 have met the needs of the dams will not meet the needs 

 of the progeny. For the latter they must be more lib- 

 eral. This explains why increased size, especially in 

 crossing and grading, results in failure when the food 

 given is not sufficiently liberal. 



When crossing is legitimate — Ordinarily the crossing 



