The following checklist describes the inputs, outputs and functionality required for a typical enterprise simulation model as a basis for discussions with a prospective farm management consultant to determine the level of analysis they can provide you. The trade-offs between technical accuracy, speed/ease of use and cost of service are always a challenge, but it is important you know what is required and what your consultant can provide.
Contact your farm management consultant for a list of suitable products to help you develop a beef enterprise model.
Input functions
Animal feed demand:
• Stock numbers x feed requirements (MJ ME) per head for each class of stock
• Animal intakes capped at biological maximum. Accounts for liveweight, liveweight gain (monthly), physiological state, eg pregnancy
• Affected by breed/mature size
• User specifics:
– mating date commencement
– mating duration
– monthly body weight change
– start weight
– weaning age
Ideally stock will include all farmed animals, as well as beef cattle to reflect the whole farm impacts.
Potential pasture growth
The pasture growth potential in an average year depends on the maintenance of pasture cover within optimum levels for growth. Information can be obtained from property pasture growth cages that exclude grazing livestock, or derived from working backwards from animal demands based on stocking rates and animal performance of the specific farm. Some models use historical databases for this information.
A function to vary pasture growth based on soil moisture/forecast rainfall levels is useful.
Cost/benefit impact of nitrogen/phosphorus fertiliser needs to be identified.
Supplements conserved and fed
• Taking into account animal requirements supplied by supplements, plus impacts on minimum pasture cover requirements
• For supplements made (including forage crops), account for impact on effective land area
Effective land area
Area in pasture – allows for changes through:
• cash or forage
• hay/silage conservation
• re-sowing
Capacity to adjust effective land area on at least a monthly basis throughout year.
Market prices
• Animal values (c/kg) for breeding, store and finished stock
• Price varied by market, grade, and time of year
• Ideally, the model should be updated by entering the ‘main indicator prices’ and ‘default correlations’ to produce a pricing forecast
Variable costs
Including:
• Opportunity cost of capital invested in livestock that can be derived from liveweights and pricing inputs; able to be calculated frequently
• Animal health – default cost per head or per DSE
• Supplementary feeds – to make, to buy/sell
• Re-sowing
• Fertiliser
• Commission and levies (or adjust in pricing module)
Outputs
Biological feasibility:
• Assessment of whether metabolisable energy (ME) availability is sufficient to achieve animal requirements
Forecast pasture cover:
• Quantity kg DM/ha
• Quality – MJM E/kg of dry matter, forecast plant growth stage reported monthly as a whole farm average
Gross margin:
•$/ha
• c/kg of DM consumed
Partial budget function to include:
• Returns – $/head* – sales and purchases
• Marginal costs – including opportunity cost of capital invested in livestock
• Closing stock numbers, weights and pasture covers equivalent to opening, ie static state
• Pasture utilisation %
• Annual feed demands (met by pasture) divided by potential pasture growth
• kg meat/ha/100mm effective rainfall
