Southern Dairy Hub

The Southern Dairy Hub was established in response to Southland and Otago farmers wanting dairy challenges in the region to be addressed through local research and demonstration.

Farm systems comparison

Four farmlets comprising both standard and lower impact kale and fodder beet systems were set up in 2018 to address farmer concerns around wintering, fodder beet feeding, and meeting nutrient loss reduction targets.

Kale system - farmlets 1 and 2

Kale is used as a wintering crop alongside in-shed feeding as a supplement to lactation. Note: the numbers in the tables below are 2019-20 season values.

Fodder beet system - farmlets 3 and 4

Fodder beet is used as a wintering crop and as a lactation supplement during spring and autumn.

Greenhouse Gas

The Greenhouse gas (GHG) footprint of the four comparison farmlets was calculated in the context of proposed He Waka Eke Noa emissions reporting for the 2019-20 season.

The footprints were broken down into contributions from different parts of the farm systems, and some potential costs were calculated based on indicative emissions price estimates.

At the SDH March 2022 Field Day, AgResearch Senior Scientist Tony van der Weerden discussed the GHG footprints of the four SDH farmlets in the context of proposed He Waka Eke Noa emissions reporting and potential pricings. Check out the highlights from his presentation below.

GHG emissions – key results

The effect of a Lower Impact system (reduced N fertiliser and supplement use and thus lower stocking rate) had a much larger effect on GHG footprints than the choice of crop type, but came at a significant cost to profitability:

• The LI systems had 20% lower methane footprint and 35% lower long-lived gas footprint than the Standard farmlet systems.
• The Fodder beet systems had a 9% lower methane footprint and 13% lower long-lived gas footprint than the Kale systems.
• The reduced N inputs in the LI systems also resulted in a reduction in direct and indirect N2O emissions from fertiliser use and from urine and dung deposition.
• It is important to note that although there were lower GHG emissions for the LI systems, this came at a significant cost to profitability.
• Methane (CH4) emissions from different parts of the farm systems.
• Nitrous Oxide (N2O) and Carbon Dioxide (CO2) emissions emitted.
• Methane (CH4) emissions from different parts of the farm systems.

Disclaimer: All prices used for this research are based on the He Waka Eke Noa pricing proposal that was released in June 2022. These are all indicative and estimates and the actual prices will not be confirmed until 2025 with the system to price agricultural emissions being decided on by the end of 2022.

Funding partners

The Participatory Research: Enhanced Research Adoption project, is part of DairyNZ’s research work with the Southern Dairy Hub. It started in July 2019 and ends in June 2022. It’s led by DairyNZ, run jointly with AgResearch, and funded by the Ministry for Primary Industries’ Sustainable Farming Fund. DairyNZ and the South Island Dairy Event are co-funders.

Winter feed crop

The winter crop feed study tested different winter feeding options and their carry over effects into lactation.

There is a growing concern about animal health and welfare issues when cows consume high quantities of fodder beet (FB), as the high-energy feed is deficient in some essential minerals (e.g. phosphorus) and low in protein. Regular updates tracking the progress of the treatments were published during the 17-18 season and a summary of results were presented in the November 17 and March 18 Field day notes.

Treatments

Treatments were chosen to demonstrate differences between two feeding strategies; ad-lib feed allocation (high) and body condition score (BCS) targeted feed allocation (target).

These strategies were implemented with both kale and fodder beet.

High allocation cows were offered 3 kg DM/cow/day baleage and ad-lib crop to achieve 1.25 BCS gain.

The target allocation cows were offered 4.5 kg DM/cow/day baleage and crop to achieve a 0.7 BCS gain.

Accounting for differences in feed quality and utilisation, cows were expected to be consuming 160 MJME/cow/day (high) or 140 MJME/cow/day (target).

This resulted in four herds of 80 cows each; high kale, target kale, high FB and target FB. Transitioning to crop commenced on the 31/5/17.

Following the winter period, cows from each treatment will be evenly dispersed between the four herds that will be running during the season at SDH. All herds will be managed under the same control decision rules until autumn 2018.

Measurements during winter

• Crop yield assessment; fortnightly throughout the feeding period
• Crop refusal assessment; two occasions during the winter feeding period
• Fortnightly crop and baleage quality
• Fortnightly BCS
• Blood samples for metabolic/mineral profile during transitioning onto the crop and through the winter
• Behaviour (lying time, standing time)
  
  

Measurements during lactation

• Colostrum quality
• Blood samples for metabolic profile during early lactation
• Daily milk volume and liveweight
• Fortnightly herd test (milk composition)
• Fortnightly BCS
• Reproductive parameters; submission rate, in-calf conception rate
• All animal health incidences during winter, calving and early lactation documented

Research articles

• Impact of winter fodder beet or kale allocation on body condition score gain and early lactation performance of dairy cows