The model determines stocking rate, proportion of area in forage species (ryegrass, kikuyu, lucerne), and seasonality of calving for a dairy farm in New South Wales (Australia). It has a three month time step, and can be constrained to calve all year round.
This model fits easily into a spreadsheet, and can be solved by Lindo's Whatsbest or similar options.
Here it has been implemented in gams, and can be run, though it may require a license.
The assignment required the a mock consultancy report, available on request, though I intend to add to ResearchGate in the future.
More complex models answering similar questions with better data, more sophisticated nutritional models, and accounting for risk are also available: https://github.com/markbneal/dairy_lp_neal_thesis_1999 https://github.com/markbneal/dairy_lp_neal_JDS_2007