Farm Planning: How Much to Grow and Rear


Parameters

Table 8.1 shows the parameters that are used in this example.

Table 8.1: Parameters

Parameter Name

Interpretation

init_num_cows[age]

Initial number of cows of each age

acres_needed[age]

Number of acres needed to support a cow of each age

annual_loss[age]

Annual percentage loss per cow of each age

bullock_yield[age]

Number of bullocks yielded per year per cow of each age

heifer_yield[age]

Number of heifers yielded per year per cow of each age

milk_revenue[age]

Milk revenue per year per cow of each age

grain_req[age]

Tons of grain required per year per cow of each age

sugar_beet_req[age]

Tons of sugar beet required per year per cow of each age

cow_labour_req[age]

Number of labour hours required per year per cow of each age

cow_other_costs[age]

Other costs per year per cow of each age

acres[group]

Number of acres per group

grain_yield[group]

Tons of grain yielded per acre by each group

yearly_loan_payment

Amount of yearly loan payment per capital outlay

num_years

Number of years in planning horizon

num_acres

Number of acres in farm

bullock_revenue

Revenue for selling a bullock

heifer_revenue

Revenue for selling a heifer

dairy_cow_selling_age

Age by which a dairy cow is sold

dairy_cow_selling_revenue

Revenue for selling a dairy cow

max_num_cows

Maximum number of cows that can be housed at present

sugar_beet_yield

Tons of sugar beet yielded per acre

grain_cost

Cost per ton of grain bought

grain_revenue

Revenue per ton of grain sold

grain_labour_req

Number of labour hours required per year per acre of grain

grain_other_costs

Other costs per year per acre of grain

sugar_beet_cost

Cost per ton of sugar beet bought

sugar_beet_revenue

Revenue per ton of sugar beet sold

sugar_beet_labour_req

Number of labour hours required per year per acre of sugar beet

sugar_beet_other_costs

Other costs per year per acre of sugar beet

nominal_labour_cost

Present labour costs for farm per year

nominal_labour_hours

Maximum number of labour hours available without incurring additional labour costs

excess_labour_cost

Cost per hour of additional labour

capital_outlay_unit

Capital outlay per additional cow beyond max_num_cows

num_loan_years

Number of years for loan

annual_interest_rate

Annual interest rate for loan

max_decrease_ratio

Maximum relative decrease in total number of cows at end of planning horizon

max_increase_ratio

Maximum relative increase in total number of cows at end of planning horizon