Computer‐Aided Evaluation of Forage Management: Forage Manager

ABSTRACTForage management decisions can have a profound impact on ruminant livestock production systems. But the importance of forage management is difficult to convey to students, because forages are often an input in animal systems and not the end product. The complexity of the system makes it difficult to clearly demonstrate the relationships of forage management to the total enterprise. The Forage Manager spreadsheet was developed as a forage management teaching tool to integrate agronomic, livestock, and cost data to demonstrate the impact of forage management on livestock production costs. Crop yield and quality, livestock class and performance, and forage and supplement costs are the inputs. Diets for the specified livestock are formulated for each forage by using corn (Zea mays L.) and soybean [Glycine max. (L.) Merr.] meal as supplements, when necessary, to balance diets for energy and protein. Forage management alternatives are compared based on total feed costs, although net returns can be calculated. Basic principles of forage management can be readily illustrated using the Forage Manager in a demonstration format or as part of recitation or laboratory assignments. The program is simple and easy to use, with menus and macros included to simplify many operations. The spreadsheet is limited in some aspects, however, because pastures are not included, diets are not recalculated as animals gain weight, and some information must be obtained from manual calculation or iteration. Despite these limitations, projects can easily be devised to teach students the importance and complexity of forage management decisions. The spreadsheet format will allow advanced projects to be developed in which students modify the Forage Manager for a specific application.