Pasture Profit Index
Why is this research important?
Given the critical importance of pasture productivity to the profitability of the Irish livestock sectors, the further development and refinement of pastures is of critical importance. The Pasture Profit Index (PPI) is a variety selection tool for perennial ryegrass varieties used by farmers and the wider seed industry to choose the optimum varieties for their farming system. Variety agronomic performance for a trait is expressed as a monetary value (€/ha) which represents the additional net profit per year by selecting that variety when reseeding. The PPI is derived from data collected by the Department of Agriculture, Food and the Marine’s Recommended List trials team and from Teagasc Moorepark. The PPI is made up of sub-indices or traits including seasonal herbage yield, herbage quality, silage yield, persistence and grazing utilisation. The PPI is published annually by the Department of Agriculture, Food and the Marine within the Recommended List evaluation program. The criteria for the addition of new varieties to the Recommend List is based on candidate varieties displaying improvement over currently available varieties. High total PPI values confirm this improvement. Dairy farmers using the list can select varieties based on their total PPI or based on high values in traits of interest to that farmer.
In addition to the PPI, Teagasc also conducts on-farm variety evaluations across Ireland in association with grassland farmers who have demonstrated high levels of grassland management capability. The herbage yield potential of variety is measured using PastureBase Ireland as the farmer completes their weekly farm walks. A robust database now exists for many varieties with many farm and sowing year replications. Clear varietal differences in herbage yield potential have been recorded in the study with strong agreement between the PPI yield sub-indices and on-farm performance.
What the research tells us
In the last two years a new trait, Grazing Utilisation, has been added to the PPI. Prior to the introduction of this trait, there was a lack of linkage between the grazing animal and variety grazing performance. Variety grazing utilisation is expressed through a star rating, 5 star varieties are consistently grazed to target post-grazing heights while 1 star varieties tend to be difficult to graze to such levels and as a result require increased topping. The trait has been very well received by the industry, particularly dairy farmers. The future focus of the PPI will be to identify the grazing complementarity of grass varieties and clover. Other studies are investigating the influence of clover on grazing utilisation. There is ongoing research to develop a new clover variety selection tool called the Carbon Profit Index. Comparable to the PPI, this index will utilise data from the DAFM white clover variety evaluation trials and Teagasc Moorepark grazing trials to develop a clover variety selection tool for the industry. It will provide new varietal information such as clover nutritive quality and nitrogen fixation.
Outputs
- Teagasc PPI webpage
- Grass and clover Recommended List 2024
- The principles of reseeding
- Updates to the pasture profit index for 2023
- Dry matter production persistence of perennial ryegrass swards on commercial grassland farms
- Incorporation of the grazing utilization subindex and new updates to the Pasture Profit Index
Contacts
Prof. Michael O’Donovan, Head of Grassland Science, Teagasc Michael.ODonovan@teagasc.ie
Dr. Tomás Tubritt, Grassland Research Officer, Teagasc Moorepark Tomas.Tubritt@teagasc.ie