[Diseases of calves].

calf is placed in an individual pen, 5 by I o by 3 feet, where it remains until it is 4 to 6 months old, depending on the size of the calf. Moving the calf and its pen, preferably uphill, once each week, takes the calf away from its contamination before too many of the oöcysts sporulate. The calves are not completely freed of infection, but they swallow enough oöcysts to get slight, nonclinical coccidiosis and to develop sufficient immunity to be resistant when they are placed on pasture, unless the pasture is heavily contaminated by older cattle. Calves raised in portable pens and then placed on pasture are no more susceptible to coccidiosis and other parasitic diseases than are calves raised in individual stalls in a conventional calf barn. Besides preventing clinical coccidiosis, portable pens reduce the transmission of w^orm parasites and many other infectious diseases of calves. As 317