[Illustration: Fig. 163. Turkey hen with brood. (Photograph from the Bureau of Animal Industry, United States Department of Agriculture)]
After the young turkeys are five or six weeks old, they do not need such close watching. They are now so well feathered that their plumage sheds rain, and if they are thrifty, a little wetting will not hurt them. It is at this age that the symptoms of the disease called _blackhead_ begin to appear, if it is present, and the turkeys pine away and die one by one. Blackhead is a contagious liver disease which affects fowls as well as turkeys, but is most fatal to young turkeys, because it is a filth disease; as has been said, turkeys are especially sensitive to foul conditions, and the young of all kinds of poultry are more sensitive to such conditions than the adults. The germs of the disease pass into the soil with the excrement of affected birds and may remain there for several years. Young birds feeding on land containing these germs may take up some with their food. If the birds are vigorous and thrifty and the land is not badly infected, no harm may be done, but if the birds are weakly and the land is so badly infected that they are constantly taking up more germs, the disease soon develops in acute form.
[Illustration: Fig. 164. Driving turkeys to market in Tennessee. (Photograph from the Bureau of Animal Industry, United States Department of Agriculture)]
Many people suppose that if once they have serious trouble with this disease, it is useless for them to try to grow turkeys, but this is an error. The germs of the disease are destroyed by cultivating the land and exposing them to the sun and air. Three or four years of cultivation will rid a piece of land of disease germs, no matter how badly it is affected. The infection is not usually distributed in dangerous quantities all over a farm or all over the land on which the turkeys and fowls have ranged. It is principally on the land near the farm buildings. There would be very little danger from diseases of this kind on farms if those who feed the poultry would make it a practice to scatter food on clean grass or cultivated ground at a little distance from the buildings, instead of giving it (as too many do) on ground that is bare year after year and never cultivated.