20 
farmers' bulletin 840. 
niako further o-rowtli for later use. Cowpeas are good for the older 
sheep, thoiio-h unpalatable to lambs. Bermuda grass, when kept 
short, is especially good when reinforced by lespedeza and bur 
clover, which grow at difi'erent seasons from the Bermuda grass and 
here find their best use as a sheep pasture. The afteiTnath of grain 
and timothy fields furnishes feed for many flocks and helps greatly 
to bring down the cost of carrying the flock through the summer. 
AVOIDING STOMACH WORMS. 
In many farming sections the flockmaster's most serious troubles 
are likely to be caused by internal parasites, the effects of which are 
j^.articularly evident during the later part of the pasture season, 
(^f these parasites the stomach Avorm is the most common and trou- 
blesome. It occurs wherever climatic conditions and methods of 
keeping the flock are favorable for its development, which means 
on most farms, and probabW all. No practicable means of entirely 
avoiding infection with this parasite has been discovered, but by 
proper arrangement of the summer pasturage it is possible to keep 
the numbers of the worms below the danger point. A knowledge of 
the development of this parasite affords a basis for the changing of 
pastures that insures a healthy condition of the flock. 
The stomach worms live in the fourth stomach.^ They are from 
one-half to 1^ inches long and have a fine red stripe running in 
spirals from end to end of the body. Their eggs pass out in the 
droppings of the sheep and hatch in a few hours, days, or weeks, 
according as the temperature is high or low. At temperatures lower 
than about 40° F. development is arrested. The larva which hatches 
from the egg crawls up on the grass blades when they are moist, 
and after attaching itself to the blade may be swallowed by some 
animal. The eggs are frequently killed by freezing or drying, but 
the larva? will sometimes live for months and can withstand re- 
peated freezings. After being taken into the body of a ruminating 
animal they develop into the mature worms. Cattle and goats also 
act as hosts to these worms but usually are not so seriously affected 
as sheep. 
The injurious action of stomach worms may be attributed to two 
things : First, the loss of blood extracted by the parasites and the loss 
of nutritive materials which may be absorbed by them from the ali- 
mentary fluids; and, second, the destruction of red corpuscles by a 
poisonous substance secreted by the parasites which is absorbed into 
the blood. Lambs that are affected become pale, thin, and weak 
and may either die or continue for a long time in poor condition and 
fail to grow as they should. The absorption of blood from the lambs 
1 The information here given with regard to stomach worms is mostlj^ taken from 
Bureau of Animal Industry Circular 157, written by B. H. Ransom. 
