164 SHEEP FARMING IN AMERICA 



that there is no longer any profit in keeping sheep 

 there. 



Most of the trouble comes from the internal para- 

 sites, and while there is a long list of them that afflict 

 sheep nearly all the trouble in our country comes 

 from two or three species. By far the most preva- 

 lent and troublesome is the twisted stomach worm 

 (Haemonchus contortus). This inhabits the fourth 

 stomach of the ewe and she carries it through the 

 winter even though she may seem to be in good 

 health. In spring and during summer the worms 

 become filled with eggs, " ripen" and pass away. 

 Just how the young germs then re-enter the sheep 

 or find a home in the more tender stomach of the 

 young lambs no one knows. They probably hatch 

 in shallow pools of stagnant water (infections in 

 Texas and New Mexico are thought to be by this 

 means) or they attach themselves to the moist grass 

 close to the ground and are taken in from that posi- 

 tion. It is noticed that old and rich sheep pastures 

 covered with short, sweet grass are frequently the 

 most fatal to young lambs even when there is no 

 stagnant water in them. 



It is not too much to say that the stomach worm 

 has done more to discourage sheep husbandry in 

 the cornbelt of America than all other causes put to- 

 gether and many a man has gone out of business 

 from the depredations of this little enemy who did 

 not even know that such a pest existed. 



The symptoms of infection from stomach worms 

 are, first : the wool appears lusterless and if pressed 



