This research programme will investigate the human, animal and pasture response to milking three times in two days (3-in-2). The project, Flexible Milking for Healthier People and Cows, started in July 2019 and will run for three years.

Project goals

• Farmers and advisers have the confidence to adopt, optimise, and support the use of 3-in-2 milking.
• Enhanced wellbeing (less hours spent working on farm and greater flexibility).
• Increased economic sustainability of farming businesses using 3-in-2 milking (through people and cow health).

Year one

The first year of the study focused on learning from farmers already using 3-in-2 strategically to help guide development of resources and information.

A farmlet trial was also set up at Lincoln University Research Farm.

Four milking frequency scenarios were tested and the impact on milk production, body condition, animal behaviour, pasture production and grazing management were measured.

• Farmlet trial details

  • Milking scenarios

    • Full season twice-a-day (TAD) (the baseline for comparison, i.e. 'control' scenario).
    • 3-in-2 from March.
    • 3-in-2 from December.
    • Full season 3-in-2.

  • Farmlet set-up

    Each farmlet:

    • will be managed independently, using the same set of decision rules
    • consists of 11 paddocks of 0.75 ha and 29 cows, resulting in a stocking rate of 3.5 cows/ha (estimated comparative stocking rate of 81)
    • will receive 150-180 kg N/ha, applied over 7 applications.

  • Grazing management

    • Between planned start of calving and balance date the rotation length will be determined by the spring rotation planner.
    • After balance date a 22 day rotation will be targeted until mid-Feb, this means each herd grazes a paddock every 2 days.
    • Herds will be allocated a fresh break after each milking, so for herds milking TAD there will be four beaks per paddock, and for herds milking 3in2 there will be three breaks per paddock.
    • Paddocks will considered for silage if forecast residuals above target for more than 3 days or if pre-grazing cover is above 3100 kg DM/ha (and feed wedge allows).
    • A 28-29 day rotation will be targeted mid-Feb to mid-April, and 44 d from mid-April to the end of May.

  • Milking times

    • After calving cows are milked once-a-day for the colostrum period and then enter their allocated herd.
    • Milking intervals are:
      • 12-18-18 for 3-in-2 and 10-14 for TAD
    • Milking times are:
      • 5am, 5pm and then 11am the following day for 3-in-2
      • 5am and 3pm for TAD.

  • Measurements

    • Weekly farm walk for pasture cover.
    • Milk volume, flow properties and liveweight will be recorded at each milking
    • Fortnightly herd test for milk composition.
    • Monthly body condition score.
    • Monthly pasture quality, botanical composition, calibration cuts.
    • Activity monitoring on all cows in the full-season 3in2 and full-season TAD herds via IceQube devices to identify time to first heat.
    • Activity monitoring on 10 cows per herd via CowManager ear tags for grazing behaviour.

Initial results from this year's work were presented in a webinar, a recording of which is available above. You'll find out about the results from year 1 of the project, how 3-in-2 might suit your farm, and what's planned for the next two years. A written summary was also published in Inside Dairy June 2020.

Year two

The project will expand to piloting 3-in-2 on commercial farms, including measures to evaluate the effects on people of moving to a 3-in-2 system. Find out more about our pilot farmers.

A second trial will be conducted to investigate the effect of different intervals used with 3-in-2 on milk production (as well as TAD and OAD).

Originally, 3-in-2 started as milking every 16 hours (16-16-16), but this has a night milking associated with it. It was then adapted to 14-16-18 and now to 12-18-18 (which was tested in the farmlets) to suit staff.

This second trial will also look at what trade-offs may exist by extending these milking intervals further to reduce the length of the day with two milkings. Five milking intervals will be tested at two snapshots in peak and mid-lactation. The intervals will be TAD (10-14), 3-in-2 (12-18-18, 10-19-19 and 8-20-20) and OAD.

Year three

The focus in this stage will be on modelling to predict outcomes in different flexible milking scenarios. For example, if a farmer wanted to go once-a-day (OAD) milking during calving (to reduce work at a busy time); then go TAD through peak lactation; then 3-in-2 through mid-lactation; and OAD near dry-off.

Dairy farmers will be given results from the project regularly and resources will be developed to help farmers make informed decisions regarding the use of 3-in-2 milking.

This project is led by DairyNZ and funded by $499,536 from the Sustainable Farming Fund and $306,914 from the DairyNZ levy.