DairyNZ senior scientist Cáthal Wims.
The DairyNZ FVI is an independent, regionspecific, profit-based index for short-term and perennial ryegrass cultivars, which allows farmers to select cultivars based on the expected economic value to their business. It categorises cultivars into five ‘star rating’ groups in each dairy region – those with a higher star rating are expected to deliver greater economic value for dairy farmers.
The FVI is supported by a comprehensive levy-funded programme of research and was launched in 2012. It’s now entering a validation phase, testing the FVI systems under realistic farm management conditions. This will give us increased confidence that the FVI’s methodology is robust and that the FVI can be trusted. Currently, the FVI includes seasonal dry matter (DM) yield only, but we plan to include metabolisable energy and persistence in the index.
Testing the FVI systems
These trials are taking place on DairyNZ’s Scott Farm, just outside Hamilton, and are managed by DairyNZ's science, technical and farm teams. Forty hectares (ha) of pasture was regrassed over the past three autumns, with equal areas sown to high- and low-ranked FVI cultivars. The high-ranked FVI cultivars were selected from the five-star rating band in the FVI for the Upper North Island, while the low-ranked FVI cultivars were selected from the one- and two-star rating bands. All cultivars were sown with white clover (standard farm practice).
Drilling of the experimental pastures at Scott Farm in March 2018.
These pastures were used to create two farm systems treatments: one based on low-ranked FVI cultivars and another based on high-ranked FVI cultivars. They’ll be compared in a three-year farm system experiment that started last month.
The aim is to determine whether DM yield differences of the cultivars emerge as expected and translate into profit rankings matching their relative FVI positions. We’ll measure milk production and pasture production; and calculate the operating profit from each system.
The Scott Farm trials are being supported by work at the Southern Dairy Hub, where 32ha was re-grassed using either high- or low-ranked FVI cultivars in February 2017 (results will be shared further down the track). This area has been managed under the Hub’s standard farm management practices, with pasture growth information collected from weekly farm walks. This will allow us to answer the question: ‘Are the predicted differences in seasonal DM yield from the FVI realised when cultivars are grown under realistic dairy farm management conditions in the Lower South Island?’
For more information on the FVI, see dairynz.co.nz/FVI You can also check out the Southern Dairy Hub’s partnership research programmes (including those on the FVI) at southerndairyhub.co.nz
Key points
- Trials have started to test the FVI systems.
- They'll compare high- and low-ranked FVI cultivars.
- This research will measure milk and pasture production, and calculate operating profit.
- This research will ensure the FVI’s methodology is robust and it’s a trusted tool for farmers.
This article was originally published in Inside Dairy July 2018
