ESTABLISHING A FLOCK AND IMPROVING IT 461 



of the variations are downward. This happens in the 

 best-regulated and best-managed flocks, but the fre- 

 quency with which culls appear decreases measurably 

 with increase in the perfection of the management. Varia- 

 tions in the degree of the vigor possessed by the parents 

 at generation and during pregnancy, lead to variations in 

 the progeny. Other influences also are probably similarly 

 operative. The time will never come, therefore, in any 

 flock when the necessity for rejecting and discarding will 

 no more exist. 



Improvement through food — Attention to the food 

 requirements cannot be too closely or too constantly ex- 

 ercised. The wisest choice of sires and the closest and 

 most intelligent selection will be in vain unless the food 

 fed is such as will maintain a high standard of improve- 

 ment. If food is to effect commensurate improvement, 

 it must be adapted: (i) To the needs of the sheep; (2) 

 to the needs of the breed; and (3) to the requirements 

 of the breeding. 



It would be correct to say that some foods given alone or 

 in combination are adapted in a general way to the feeding 

 of all classes of sheep, but it would not be correct to say 

 that such adaptation is exactly equal in the different 

 classes of sheep. 



With sheep maintained for different uses, or with 

 sheep of different breeds, with reference to the individual 

 sheep, the food should be so regulated as to meet its needs 

 at different stages of development and under different 

 conditions as to use, and it should be of a character that 

 will help to maintain much of uniformity in condition 

 throughout the year. Young lambs, for instance, must 

 have the best class of food given to the flock. After wean- 

 ing, they should be given the preference in pastures and 

 an amount of grain that would probably be wasteful if 

 fed to nature sheep at that season. Pregnant ewes should 

 be given foods that will produce much milk, while shear- 

 lings not pregnant may thrive on food different in kind 



