System Type: 1
Bay of Plenty
Last Update:
14 April 2021

DairyNZ Comment:

14 Apr 2021
  • Every autumn it’s the same dilemma – “how much longer do I milk on for?”, or “is it economic to use supplements to extend the lactation?”.  There’s some key rules that should be adhered to if you’re going to make it work economically and not compromise next season.

    To work out the return for feeding supplement on your farm check out Milksolids response to supplements - DairyNZ.  There’s a few things that need to be met if it is going to work profitably:

    • The rotation length is slowed and milking is extended (more days in milk).
    • Cows graze to target residuals of around 1500kgDM/ha
    • Total supplement wastage is kept below 20%
    • Supplement quality is more than 10.5MJME/kgDM.

    A rule of thumb is paying no more than 5% of payout/kgDM (or 3.5% if using the allowance for other costs associated with feeding the supplement).  At a $7.30/kgMS payout this equates to $260-360/tonne delivered.

    Behind calving rate, BCS at calving is the most critical factor if we are seeking to maximise reproductive performance.  The impact of not achieving BCS targets can last several seasons due to the impact of lower BCS on submission and conception rates, and ultimately calving rate the following spring. Remember that no BCS is gained in the first 10 days after drying off and the last month of pregnancy.

    A feed budget is important to determine the pasture cover targets from now until calving and to base drying off decisions on.  We can only look at continuing milking through use of supplements if we have enough autumn pasture built up to feed with the supplement and where target pasture cover for calving can be achieved.

    Supplement wastage is another important consideration.  Wastage starts in storage and occurs at every step through to the cows actually consuming it.  Up to 40% wastage can occur in storage, 50% through feeding out in the paddock and 25% when using feeding bins.

    Supplements can be used to profitably extend the lactation, but there are important caveats that need to be considered.  First and foremost, and probably most importantly, any extra days in milk must not be at the expense of either pasture cover or BCS at calving.  Tick those off and source a suitable energy supplement at the right price and it may just work!

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  • Date Collected

    14 Apr 2021

  • Soil temp


  • Growth

    64 kgs DM/day

  • APC

    2402 kgs DM/ha

  • Rainfall

    50 mm

  • BCS


  • % in milk

    100 %

  • MS/cow

    1.06 kgs

  • MS/ha

    4.04 kgs

  • MS/ha YTD

    1309 kgs

  • Rotation

    30 days

  • MS/cow YTD

    - kgs

  • Nitrogen YTD

    120 kgs/ha

  • Supplements

    2.0 kgs/cow/day

  • Supplements YTD

    672 kgs/cow

  • Weight Gain

    - kgs/day

  • Stocking Rate

    3.7 su/ha

  • Crude Protein Level


  • MJME