Resource Efficient Dairying trial: measurement criteria for farm systems over a range of resource use

Abstract

The aim of the Resource Efficient Dairying (RED) trial is to measure the productivity, economic and environmental effects of different feed inputs and management processes on a dairy farm. This is a longterm systems trial located at Scott Farm (Dexcel Research Farm) established on 1st June 2001 and expected to continue until 2006. Trial design was based on six systems that have an allowance of up to 200 kg nitrogen (N)/ha (excluding the low input treatment). They are: low input (no N fertiliser, heifers grazed-on and 2.3 cows/ha); control (3 cows/ha); standoff (3 cows/ha); low supplement input (5 t dry matter (DM) maize silage/ha, 3.8 cows/ha); moderate supplement input (10 t DM maize silage/ha; 5.2 cows/ha); and high supplement input (15 t DM maize silage + 5 t soymeal/ha; 6.9 cows/ha). The last two systems have irrigation available to boost pasture production. All systems were designed to operate at a common comparative stocking rate (CSR) of 85 kg liveweight (LW)/t DM. Two seasons' data have shown that increasing the stocking rate (SR) by 1.5 cows/ha from 3.8 to 5.3 cows/ha, plus extra feed, increased output by 90 and 184 kg milksolids (MS)/total ha in the two years, when the extra area required to supply the extra feed is included in the calculation of kg MS/ha. However the further increase to 6.9 cows/ha plus extra feed produced less MS/total ha than the system stocked at 3.8 cows/ha. Calculations of economic farm surplus (EFS) and return on assets (ROA) reveal that when the payout is $3.50/kg MS the low input system is competitive irrespective of land price ($18000 or $37000/ha) or supplement cost (18 c or 24 c/kg DM). Conversely at a higher payout of $4.50/kg MS the treatment supplemented with 10 t maize silage DM/ha is competitive over the range of land prices and supplement costs tested. Keywords: dairy cows, economic evaluation, maize silage, milksolids, nitrogen fertiliser, stocking rate