[PorkCHOP: an economic microcomputer replacement model for sows].

A computer model called PorkCHOP, was developed in an electronic spreadsheet on the microcomputer to help farmers, veterinarians and other livestock specialists reach economically sound culling decisions in swine breeding herds. It quantifies the benefits of a longer herd life and a shorter farrowing interval, calculates an economic index (Retention Pay-Off) to be used as a culling guide for individual sows within a herd and determines the maximum number of permissible services when sows fail to conceive following the first service. PorkCHOP runs with 'default' settings for the major factors affecting replacement economics, but the user can modify all variables to represent a specific herd more precisely.