Nationally, just 6.2 tonnes of grass per hectare is being utilised on Irish dairy farms. Researchers at Moorepark have set a target of 10t of grass utilised per hectare by 2020. They claim that a 1% increase in grass utilised across all sectors would be worth €27m nationally, through increased output and reduced feed costs.
Part of the action plan towards achieving that target is to make changes to the way grass varieties are selected by Irish farmers. Up to now, most varieties were selected from the recommended lists compiled by the Department of Agriculture.
Over the last few years, the Department and Teagasc have been working together to incorporate more information into the recommended lists. The result of this collaboration has been the introduction of the pasture profit index (PPI) into the recommended lists for 2015.
The first thing to note about the PPI is that it is very trait-orientated. So while the recommended lists focus on yield and quality, the PPI focuses more on the different traits that individual grass varieties have and, importantly, assigns an economic value to these traits.
In much the same way that the economic breeding index (EBI) assigns an economic value to an animal’s traits, the PPI assigns an economic value to the traits of a grass variety, traits such as seasonal growth, silage yield, grass quality and persistency. Each of these are known as sub-indices within the PPI and when combined together they form the variety’s PPI in euro per hectare per year.
Base values are determined by national average figures for grass growth and silage production and average figures for grass quality and persistency from the Department’s variety testing trials.
The objective of the PPI is twofold. Firstly, it makes it easier for farmers to select varieties that are most suited to their requirements by focusing on the sub-indices that are most relevant to them, such as spring growth or persistency, which is determined by the variety’s ground score.
Secondly, it gives plant breeders an incentive to breed varieties that are going to rank highly on the PPI, which should result in the acceleration of genetic progress in areas of grass breeding that give most economic return to Irish farmers.
Overseeing the introduction of the PPI is Teagasc researcher Michael O’Donovan.
“We now have a PPI figure for 95% of the grass varieties on the recommended list,” said Michael. “The strengths and weaknesses of each variety are now clearer to see, with more emphasis on the key traits affecting profitability. I expect that over time the pasture profit index will expand and evolve to include more sub-indices, and will be based on information from more sources, particularly on-farm recording of growth, quality and persistency under a commercial setting.”
At present, the PPI uses the data generated by the Department of Agriculture’s “simulated grazing” grass variety trials at five sites around the country. These grass plots are cut with a machine eight to ten times per year. Only varieties with two harvest years completed are included in the index. Results from the trial plots are fed into the computer model generated by the grassland research team at Teagasc and the PPI value is generated.
Topping the list for 2015 is the tetraploid variety Abergain which was bred at Aberystwyth in Wales and is distributed in Ireland by Germinal Seeds. Abergain has a PPI of €208, and scores consistently high in all the sub-indices, which is an indicator of a good all-round variety.
Abergain is closely followed by the tetraploid Dunluce, which has a PPI of €194. Two diploids, Aberchoice and Abermagic, share third spot at €184 each. The widely-used diploid Tyrella is further down the list with a PPI of €71.
So is it possible to get a PPI value for a grass seed mix using the PPI values for each individual variety and working out the proportion of each variety in the mix? No, was the answer from Michael as research has shown that the proportion of varieties in the grass seed bag is very different to the proportion of varieties in the subsequent grass sward. Michael says that unless you can accurately determine the exact breakdown of each variety in a grass sward, there will be big inaccuracies in the PPI value, especially where tetraploids and diploids are mixed.
The introduction of the PPI should be welcomed by farmers as a positive step in the development of variety testing in Ireland. The Department and Teagasc should be commended for working together to improve the information available to farmers.
However, it is important to remember that it is still very early days in the development of the PPI and it will take some time to have a real impact.
Like all good industry initiatives, it needs farmer support to drive the changes and ensure that the grass breeders and grass seed suppliers are providing varieties that Irish farmers need in order to increase the amount of grass being utilised.
That said, patience will be required as plant breeding is a notoriously slow process. As with any index, feeding more data into the PPI will improve its reliability. The more access the researchers have to on-farm grass measurements and quality recording, the more accurate the PPI will become.
The PPI should not be used in isolation when choosing a variety. Heading dates and ploidy are still important considerations when choosing varieties.
The PPI assigns an economic value (€/ha/year) to the traits of each grass variety in the Recommended List.A PPI value exists for 95% of the varieties on the Recommended List.Abergain tops the Index with a PPI of €208 followed closely by Dunluce at €194.Heading date and ploidy are still important considerations when choosing a variety.
Nationally, just 6.2 tonnes of grass per hectare is being utilised on Irish dairy farms. Researchers at Moorepark have set a target of 10t of grass utilised per hectare by 2020. They claim that a 1% increase in grass utilised across all sectors would be worth €27m nationally, through increased output and reduced feed costs.
Part of the action plan towards achieving that target is to make changes to the way grass varieties are selected by Irish farmers. Up to now, most varieties were selected from the recommended lists compiled by the Department of Agriculture.
Over the last few years, the Department and Teagasc have been working together to incorporate more information into the recommended lists. The result of this collaboration has been the introduction of the pasture profit index (PPI) into the recommended lists for 2015.
The first thing to note about the PPI is that it is very trait-orientated. So while the recommended lists focus on yield and quality, the PPI focuses more on the different traits that individual grass varieties have and, importantly, assigns an economic value to these traits.
In much the same way that the economic breeding index (EBI) assigns an economic value to an animal’s traits, the PPI assigns an economic value to the traits of a grass variety, traits such as seasonal growth, silage yield, grass quality and persistency. Each of these are known as sub-indices within the PPI and when combined together they form the variety’s PPI in euro per hectare per year.
Base values are determined by national average figures for grass growth and silage production and average figures for grass quality and persistency from the Department’s variety testing trials.
The objective of the PPI is twofold. Firstly, it makes it easier for farmers to select varieties that are most suited to their requirements by focusing on the sub-indices that are most relevant to them, such as spring growth or persistency, which is determined by the variety’s ground score.
Secondly, it gives plant breeders an incentive to breed varieties that are going to rank highly on the PPI, which should result in the acceleration of genetic progress in areas of grass breeding that give most economic return to Irish farmers.
Overseeing the introduction of the PPI is Teagasc researcher Michael O’Donovan.
“We now have a PPI figure for 95% of the grass varieties on the recommended list,” said Michael. “The strengths and weaknesses of each variety are now clearer to see, with more emphasis on the key traits affecting profitability. I expect that over time the pasture profit index will expand and evolve to include more sub-indices, and will be based on information from more sources, particularly on-farm recording of growth, quality and persistency under a commercial setting.”
At present, the PPI uses the data generated by the Department of Agriculture’s “simulated grazing” grass variety trials at five sites around the country. These grass plots are cut with a machine eight to ten times per year. Only varieties with two harvest years completed are included in the index. Results from the trial plots are fed into the computer model generated by the grassland research team at Teagasc and the PPI value is generated.
Topping the list for 2015 is the tetraploid variety Abergain which was bred at Aberystwyth in Wales and is distributed in Ireland by Germinal Seeds. Abergain has a PPI of €208, and scores consistently high in all the sub-indices, which is an indicator of a good all-round variety.
Abergain is closely followed by the tetraploid Dunluce, which has a PPI of €194. Two diploids, Aberchoice and Abermagic, share third spot at €184 each. The widely-used diploid Tyrella is further down the list with a PPI of €71.
So is it possible to get a PPI value for a grass seed mix using the PPI values for each individual variety and working out the proportion of each variety in the mix? No, was the answer from Michael as research has shown that the proportion of varieties in the grass seed bag is very different to the proportion of varieties in the subsequent grass sward. Michael says that unless you can accurately determine the exact breakdown of each variety in a grass sward, there will be big inaccuracies in the PPI value, especially where tetraploids and diploids are mixed.
The introduction of the PPI should be welcomed by farmers as a positive step in the development of variety testing in Ireland. The Department and Teagasc should be commended for working together to improve the information available to farmers.
However, it is important to remember that it is still very early days in the development of the PPI and it will take some time to have a real impact.
Like all good industry initiatives, it needs farmer support to drive the changes and ensure that the grass breeders and grass seed suppliers are providing varieties that Irish farmers need in order to increase the amount of grass being utilised.
That said, patience will be required as plant breeding is a notoriously slow process. As with any index, feeding more data into the PPI will improve its reliability. The more access the researchers have to on-farm grass measurements and quality recording, the more accurate the PPI will become.
The PPI should not be used in isolation when choosing a variety. Heading dates and ploidy are still important considerations when choosing varieties.
The PPI assigns an economic value (€/ha/year) to the traits of each grass variety in the Recommended List.A PPI value exists for 95% of the varieties on the Recommended List.Abergain tops the Index with a PPI of €208 followed closely by Dunluce at €194.Heading date and ploidy are still important considerations when choosing a variety. 
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