FARM ANIMALS 273 



allowed on pasture at all, since they naturally do not 

 eat anything but the mother's milk for about one 

 month. At the end of that period practically all 

 danger of infestation with stomach worms is past. 



Likewise, in Minnesota it has been found by a 

 long series of careful experiments that the breeding 

 habit in ewes which ordinarily drop their lambs 

 in the spring may be changed so that they will 

 produce them in the fall or early winter. This 

 change is effected in practice by crossing with 

 pure bred Dorset rams for two or three genera- 

 tions. It appears that after the changed breeding 

 habit has been brought about in the ewes a super- 

 ior quality of lambs, at least, in many instances, 

 may be obtained by using rams of a black-faced 

 breed, for example Southdowns or Shropshires. 



Lambs vs. Wethers. As with all other farm 

 animals, including chickens, so with sheep, the 

 rate of gain is greater in young than in old an- 

 imals and the cost of gain is less. This difference 

 is sufficiently great to affect the financial results in 

 breeding sheep in a pronounced manner. For 

 example, in Montana it was found that the cost 

 of feeding per day in lambs was one and two- 

 tenths cents and in wethers one and five-tenths 

 cents while the cost of a pound of gain in lambs 

 was four and five-tenths cents and in wethers 

 six and three-tenths cents. These differences, 

 while very slight in a single sheep, become a large 

 factor when it is multiplied by thousands as is the 

 case on large sheep ranches. In a subsequent 

 test of this matter in Montana it was found that 

 the cost of producing one hundred pounds of 

 meat on lambs was $4 . 18, on one-year-old wethers 

 $5 . 83, on two-year-old wethers $5 . 90 and on old 

 sheep $6.78. These differences in cost were due 



