Official websites use .gov
A
.gov website belongs to an official
government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you've safely
connected to the .gov website. Share sensitive
information only on official, secure websites.
Longitudinal surveillance data for two additional broiler farms in Pennsylvania. Symbols, colors and layout as in fig. 6. Both of these farms had four houses. Farm “D” was associated with the same operation as the farms in fig. 6, but farm “E” was not. Note also that farm “E” changed operations during our surveillance period, the timing of which is marked with an asterisk.
