Autumn Calving Trial in Taranaki at DTT

DTT Kavanagh – Autumn Calving Trial

Summer dry has been identified by farmers as being the most challenging climatic event in many coastal areas of the North Island. The average summer rainfall in coastal Taranaki is 240mm with evapotranspiration of 410mms. The result is long periods of moisture deficit, reduced pasture growth rates, and greater size and duration of feed deficits. In comparison, winter pasture growth rates have increased over the past 20 years, with more widespread use of urea and gibberellic acid, improved ryegrass cultivars, and increased soil temperatures (+1.6°C in 30 years).

To add to the incentive of feeding and milking cows during the winter, compared with summer, Fonterra and Open Country are actively pursuing more winter milk for UHT exports to China and short shelf life products that need to be made during winter. For example, Fonterra is offering winter premiums of $2.85 to $3.50 for the period 16 May to 15 July (less transport charges).

The current trial at DTT Kavanagh is investigating the benefits and costs of autumn calving. The Kavanagh farm is coastally located on the outskirts of Hawera.

Trial Outline:

  • 2x 104 ha farmlets established spring 2017 – 4-5 ha paddocks randomized for soil fertility, location/block (equal number on coastal side of farm), and equal effluent paddocks
  • Each farmlet 300 Friesian X cows – randomized, balanced herd based on age, PW, BW, LWT, calving date, MS production from previous season
  • 300 cows mated in spring 2017 and dried off in May 2018
  • 300 cows not mated in spring, milked through and mated in June 2018, then dried off in Feb 2019

Results 2017/2018 Season

  Kg MS/cow Kg MS/ha Days in milk

(up to 1 June 2018)

Cow LWT (Kg)

(March 2018)

Autumn 444 1259 296 487
Spring 402 1121 264 489
Difference +42 +138 +32  

Results 2018/2019 Season

  Kg MS/cow Kg MS/ha Days in Milk Days in Milk

Transition period

Cow LWT (Kg)

(March 2018)

Autumn 343 908 285 530 599
Spring 400 1155 275   484
Difference -57 -247      

Over the two transition years the autumn herd produced 107 kg MS/ha less than the spring herd.

Predicted production 2019/2020 Season

  Kg MS/cow Kg MS/ha
Autumn 480 1380
Spring 410 1150
Difference +70 +230

Empty Rates:

  2018/2019 2019/2020
Autumn 5% 12%
Spring 13%  

Overall, we see the benefits to an autumn calving system to include taking advantage of the winter premium milk price + the second flush in production/higher per cow production. Many farmers are also finding it to be a good lifestyle change. However, it does come at a cost with a greater amount of supplementary feed required to get through the winter feed deficit period.

Our trial is running for three seasons and we are yet to undertake a full financial analysis.

Feel free to follow the Kavanagh Farm Autumn Calving Trial progress via our weekly Farm Walk Notes, available on

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