Development of a Crossbreeding System Evaluation Tool for Cattle Producers

Summary

A spreadsheet was developed with multiple sheets, that allow comparison of different crossbreeding systems from different combinations of Australian cattle breeds. The program allows comparison of pure breeding systems, 2-way crossing systems and 3-way crossing systems. The comparison is based on system efficiency, and considers input and output from production of steers, fattening heifers and culled cows.

The program allows the user to vary the number of replacement heifers from their own herd. The input parameters (related to weights at fixed ages, fat scores, reproduction, mortality, and associated heterosis) are read from a table and a herd model is used to calculate the number of animals used for replacement and slaughter. Growth curves are derived from weights, and the feed input needed for growth and maintenance is derived and aggregated at a herd level on a monthly basis. A summary sheet allows selection of breeds, and calculation of key system parameters, such as feed needed, revenue from slaughter animals, days to slaughter, feed per kg of meat produced, and other derived parameters.

The current version of the tool should be seen as a demonstration version, and can be used as a basis for further development. Further development needs to involve

Improved logistics in the 3 way crossing system,

The addition of a composite module,

Road testing and fine tuning the technical and economic parameters

Adding into the growth curve the different degrees of fatness of the breed combinations used,

An interface that allows consultants and breeders unassisted use of the tool. The fifth point needs to involve discussions with a consultative group comprising practically-oriented researchers and end users.