A program to assess the efficiencies of sheep-meat production systems: a teaching aid

A computer program written in Visual Basic within a spreadsheet was developed to illustrate how the efficiency of a sheep-meat production system varies when changes are made in any or all of 32 variables. System performance is expressed in monetary terms as either the efficiency (E) in dollars returns per dollar cost (with a break-even value of 1) or as a profit . Costs and returns for ewes, rams and lambs are taken into account, and all are expressed on a per ewe per year basis. A single per kilogram price for mutton is used, but for lambs, the proportion falling into various classes at any carcass weight is calculated using a specified GR/carcass weight relationship in a separate simulation program. Relationships within the E-program are based on published data, such as those in lamb feed requirement tables. This program has proved useful as an aid to evaluating some repercussions of making various combinations of changes to sheep-meat production systems.