Supplement Trial Update 17 Dec 20

This project compares three farms with different supplement use on production, profit and environmental impact. The three farm systems are:

  1. Pasture Only Farm – No imported supplement – 2.7 cows/ha
  2. PKE Only Farm – PKE used to fill feed gaps within milk FEI limits – 3.1 cows/ha
  3. PKE Plus Farm – PKE used until milk FEI limit and then other supplements added – 3.1 cows/ha

This project is funded by DairyNZ, MPI (Sustainable Farming Fund) and Hine Rangi Trust.

17th December 2020 Pasture Only Farm PKE Only Farm PKE Plus Farm
Farm Area (ha) 28 28 28
Average Pasture Cover (kg DM/ha) 2139 2204 2165
Pasture Growth (kg DM/ha/d, last 2 weeks) 36
Rotation Length (days) 33 30 33
Cows in milk/total cows 77/77 87/87 86/86
Production/cow/day (kg MS) 1.42 1.47 1.45
Production/ha/day (kg MS) 3.91 4.58 4.46
Production – Season to date (kg MS/ha) 606 738 792
Supplement Fed (kg DM/cow/day) 0 1.6 PKE 1.7 PKE
Supplement Fed – Season to date

(kg DM/cow)

181 Silage 338 PKE 317 PKE

147 DDG/SH

Average Body Condition Score 4.1 4.0 4.0
Proportion cows under BCS 4.0 8% 12% 16%
Worry Score (1 = Low, 10 = High) 5 6 4
Nitrogen – Season to Date (kg N/ha) 174 172 168
Milk FEI A B B
Rainfall (mm last 2 weeks) 12 mm


  • Pre-graze pasture covers are dropping fast and residuals starting to drop too, so PKE feeding will be maximised as FEI allows, and DDG will be added to the PKE Plus diet
  • Discussion centred around levers to pull if it rains or doesn’t rain
  • All herds will remain on current rotation lengths of around 30 days
  • If good rain and growth occurs we will pull supplement out and if needed drop paddocks out to maintain residuals on kikuyu
  • If no rain and growth stays low we will increase DDG to the PKE Plus herd.
  • The PKE Only herd may use some silage to top up intakes.
  • The Pasture Only herd has very limited silage so will save this for later and meanwhile use OAD to reduce feed demand when production drops below 1.2kgMS/c/d.
  • All cows get their first PD early January to get accurate dates.
  • We are monitoring spore counts to watch facial eczema loading and may start zinc trough treatment