An EU farming review has raised concerns around the environmental benefits being delivered by Ireland's €300m Beef Data and Genomics Programme (BDGP).
The review of CAP spending, carried out for the Commission, questioned the use of environmental funding to support the BDGP.
It said that, while the scheme does seek to reduce greenhouse gas (GHG) emissions per head of livestock "it does not address wider questions around climate-proofing farming".
In response, the Department of Agriculture said that although a longer time frame is necessary to evaluate the cumulative benefits associated with genetic improvements attributed to the BDGP, preliminary evidence indicates positive gains in performance. These gains are expected to be permanent and cumulative, it said.
However, it also confirmed that the programme has been the subject of a spending review by the Irish Government Economic & Evaluation Service, which is expected to be published soon.
At the outset of the scheme which was launched in June 2015, the Department of Agriculture said that in improving from the average 3 star cow to a 5 star cow, the potential GHG reduction is approximately 86kt CO2 eq per year by 2020, which is equivalent to 4.4pc of marginal abatement potential from the suckler herd.
It claimed that as the suckler breeding evolves, the breeding index would also improve so that the current top 1pc of animals could form the norm by 2030. It said the cumulative climate mitigation benefits from this outcome are projected at 1.9 Mt CO2 by 2030 or 235,000 tonnes of CO2 annually in 2030.
It comes as the Irish Cattle Breeding Federation (ICBF) '5 Year Trend' reports, which were sent to 24,500 herds participating in BDGP earlier this spring, found that herds had an average of 26 cows in 2018, an increase of two over the 2014 average of 24 cows.
Non-BDGP herds have decreased in size over the same period with the average herd falling to 16 cows in 2018 from 17 cows in 2014. Data from the reports released recently by the ICBF also found that BDGP herds have improved calving interval by four days more with calves/cow/year increasing at the same rate, though non-BDGP herds are coming from a lower base.
The percentage of heifers calved at 22-26 months has improved by 3pc more in BDGP herds.
However, it also found that there is very little movement on the six-week calving rate across both sets of herds.
ICBF noted that the six-week calving rate is actually higher in non-BDGP herds, but it has to be noted that these herds are significantly smaller with an average of 16 cows versus an average of 26 cows in BDGP herds.
Smaller herds have an advantage when it comes to achieving a high six-week calving rate. Commenting on the figures, the ICBF explained that replacement heifers bred on the back of better breeding decisions since the start of the programme are now starting to calve down.
"This analysis gives a very early picture of where the BDGP is taking the national suckler herd.
"As more and more high index replacements enter the national herd and the upward trajectory of the Replacement Index continues, further significant gains should be made in key efficiency metrics such as calving interval and calves/cow/year," it said.
The scheme is one of a range of measures to address carbon neutrality in agriculture as part of a wider strategy on abatement, sequestration and displacement of energy sources.