Enhancing levels of sustainability within the beef sector has been recognised as a key climate change target for agriculture across the island of Ireland.
In addition, the significant numbers of cattle maintained on Irish farms means that the total volume of methane emissions represents the greatest environmental challenge facing Ireland’s red meat industry.
These were two of the key messages delivered at the recent Agri-Food and Biosciences’ Institute (AFBI) beef and sheep open day.
Approximately, 500 farmers from across the island of Ireland attended the event.
Reducing age at slaughter
According to AFBI’s Dr. Francis Lively, reducing slaughter age is a very practical and achievable method to reduce methane production and optimise profit.
This can be achieved by setting growth targets throughout the life of the animal. Having accurate feed analysis is also critical to develop a nutritional plan to meet a good slaughter weight at a lower age.
Regular monitoring of performance is necessary to ensure targets are being achieved, improving forage.
According to Francis Lively, maintaining a liveweight gain figure of 0.6kg/day throughout an animal’s life will deliver significant reductions in slaughter age, while still maintaining carcass weight and shape.
“This figure relates to heifers and steers of all breed types. Essentially the days of putting cattle through a store period are over,” Lively explained.
“Meeting these targets will entail beef farmers providing top quality grazing opportunities for stock and making silage of a similar quality, which can be fed during the winter months.”
The AFBI scientist admitted that achieving a reduced age at slaughter will be a more straightforward challenge with native breed cattle.
Nutrient managemant
Making best use of the nutrients already available on livestock farms was another of the key themes addressed over the two days.
“Slurries represent valuable sources of organic nitrogen and phosphorous,” AFBI director, Prof. Elizabeth Magowan, explained.
“So ensuring that these nutrients are made available at those times when plant uptake is optimal delivers two critically important end results.
“These are – a reduction in nutrient run-off into streams and other water courses plus a reduction in the amounts of chemical fertilisers required to secure optimal crop yields.
“So we end up with a win/win scenario for farmers. AFBI research is also looking at ways of reducing nitrous oxide and ammonia emissions to the atmosphere, two issues that must be actively addressed by agriculture as a whole,” she added.
She also said that bespoke research and development work is delivering tangible responses to these challenges, the use of low emission slurry spreading (LESS) equipment being a case in point.
“But the AFBI research teams realise that one-size-fits-all solutions will not work across the networks of farms that make up agriculture in Northern Ireland,” she continued.
“And, again, our programmes has been developed to reflect this situation.”
Delivering change at least cost
The AFBI director cited the use of the Bovine Information System (BovIS) management tool as an example of how beef farmers can secure real change within their businesses at the least cost.
This ‘decision support tool’ was funded by Department of Agriculture, Environment and Rural Affairs (DAERA) and AgriSearch and the application was developed by AFBI to provide Northern Ireland beef producers a facility to view, analyse and rank the performance of slaughtered animals.
BovIS holds carcass information from Northern Ireland’s processors and farmers historic and current herd information.
Farmers can log into BovIS via the Government Gateway and view information relating to animals they have killed.
DAERA recently introduced a new Beef Carbon Reduction Scheme (BCRS) aimed at reducing greenhouse gas (GHG) emissions and improving efficiency in the beef sector.
The new measure rewards farmers with a £75/head payment from April 2024 for animals slaughtered at, or below, the target age of 30 months in year 1 of the scheme reducing to 26 months in year 4.
According to Elizabeth Magowan, BovIS has a pivotal role to play in helping farmers benefit from the BCRS through understanding their historic and current herd performance.
BovIS support tools include: Herd of Origin Report; Carcass Benchmarking; and the Growth Rate Calculator.
“Bovis is currently telling us that 33% of cattle slaughtered in NI are achieving carcass weights of 280kg and over at, or before, 24 months-of-age,” Prof. Magowan said.
“Making best use of BovIS requires access to a weighbridge on farm. If these are not available, they can be accessed at reasonable cost.”
A specific, least-cost development option for dairy farmers is the adoption of lower phosphorus diets.
This approach has been shown to reduce phosphorus excretion in manure by up to 45%.
A further reduction in the phosphorus content of dairy cow concentrates, from the agreed target of 5.7g/kg to 5.2g/kg (fresh) could reduce quantities of excess phosphorus on local dairy farms by approximately 350t per year.
Reducing the crude protein content of the diet can reduce nitrogen excretion in manure by around 15%, and ammonia emissions from the resultant slurry by up to 30%.
Breeding for the future
Cattle and sheep are highly efficient in converting grass and other forages into beef, milk and lamb. The drawback is their production of methane, an important GHG, as a by-product.
However, under the same farm conditions, there will be variations in relation to the amount of methane produced by animals within the same group.
These were the key messages delivered by Sam Boone, who heads up the Signet sheep breeding programme at Agriculture and Horticulture Development Board (AHDB), as part of his presentation to the AFBI beef and sheep open day.
“Some of the differences in methane production levels achieved by ruminant livestock can be attributed to genetic factors,” Boone stated.
“The beauty of genetics is that, unlike health and nutrition, it delivers a cumulative benefit across the generations.
“And it’s locked in. So, where health is concerned, we do a treatment this year and it impacts on the animals. But we have to do the same thing again next year in order to keep this going.
“But with genetics we can build on the process; it delivers a cumulative impact which is sustainable into the future within a population.”
According to Boone, the benefit of genetic improvement, secured over the past 40 years, is now worth about £14 million on an annual basis.
“The equivalent figure for the beef sector works out at £7 million to the beef industry,” Boone further explained.
There are two ways of reducing methane output within the ruminant livestock sectors. One is through direct selection.
“The other is through a process of indirect selection,” Boone commented.
Direct selection involves the actual measurement of the methane emissions produced by livestock. Where sheep are concerned, this work is carried out under the auspices of the ‘Breed for Change’ programme.
“We are measuring methane production levels under commercial production environments, courtesy of sheep within an actual grazing environment,” Boone continued.
“This is the gold standard approach. The approach is also allowing us to CT scan the sheep involved in the trial. This allows us to measure rumen volumes. It should be possible to gauge how this relates to actual methane production levels.”
The AHDB representative admitted that it is harder to measure methane emission levels with cattle.
“Cattle are that much bigger,” he added.
“The way around this challenge is to measure the feed efficiency of the animals. We know there is a high degree of correlation between the efficiency with which animals convert feed intake into meat or milk, and the associated levels of methane that are produced.”
Indirect selection involves the assessment of efficiency-related indices.
“Where dairy sires are concerned, the availability of an enviro index is now available,” Boone commented.
“So we also know that there is a more general association between growth rates, feed conversion and maternal traits, linked to the overall efficiency secured within a beef and sheep enterprise.
“The higher the levels of efficiency secured, then the lower will be the levels of associated methane that are produced.”