Adopting improved livestock farming practises can simultaneously mitigate the production of both greenhouse gases and ammonia, according to Teagasc’s director of research Professor Frank O’Mara, writes Richard Halleron.
He made this comment while speaking at the recent Alltech European Technical summit, held in Dublin. The overarching theme of the event was: Embracing Agriculture’s New Norms.
O’Mara went on to point out that Teagasc research has confirmed that the objective of putting production agriculture on a ‘sustainable intensification’ footing can be achieved.
“We now know that improving the genetic merit of beef and dairy cattle can have a very beneficial impact on a farm’s Carbon Footprint. The same can be said for improved grassland management practices.”
He added:“The inclusion of clover in grass swards will also help to reduce greenhouse gas and ammonia production.”
O’Mara also discussed a number of important input options that can have a very significant impact on a farm’s Carbon Footprint value.
“The use of protected urea is a real game changer in this regard,” he stressed.
“Research has confirmed that this product can be used successfully on grassland throughout the growing season.”
The Teagasc director continued:“Making better use of slurry is crucial on all dairy and beef farms as we look to the future,” he stressed.
“Techniques such as injection and trailing shoe spreading systems are much more effective than the traditional use of a splash plate, where slurry utilisation is concerned. The downside to these approaches, however, is the associated cost.”
O’Mara confirmed the role of evolving research in identifying new ways of reducing greenhouse gas and ammonia emission levels.
“The real challenge moving forward will be that of encouraging farmers to utilise the new technologies that come on stream. National governments will have a key role to play in this regard,” he said.
Significantly, O’Mara indicated that feeding cattle total mixed ration (TMR) diets – compared with high quality grazed grass – did very little to improve the Carbon Footprint of a ruminant production system.
This seemed to be slightly at odds with the comments made by Dr Tim Snellling, a research scientist at Harper Adams’ University, who said that forage-based diets are more likely to lead to higher levels of greenhouse gas production.
“Grass and silage-based diets encourage a microbial population in the rumen which is more disposed to producing methane,” he said.
“Research trials have confirmed a clear association between dietary fibre levels and methane production. In other words, the higher the concentrate fraction of the diet, the lower the potential for methane production.”
Snelling explained that methane is produced when Carbon Dioxide combines with Hydrogen in the rumen.
He also confirmed that grazed grass is a perfectly natural feed for ruminant animals.
“But, from an environmental point of view, it’s a question of balance. Suckler cows grazing upland pastures, for example, bring a very positive environmental dimension to the way in which farmers manage their land. At a very fundamental level, the cows encourage a wide variety of grasses and other plants to grow, which help maintain and improve biodiversity.”
Snelling said that research is helping to identify inhibitors that can target the chemical pathways that lead to the production of methane in the rumen. He added: “Nitrate is one such inhibitor that has already been identified. A number of plant oils also act as inhibitors, when it comes to the production of methane in the rumen. Downsides to the use of these products include their cost and identifying the best way of including them in animal diets.”
Dr Stephen Ross, a senior sustainability speciality with Alltech E-CO2, explained that decreasing the environmental impact of a farming business will, by default, improve its profitability.
Where dairying is concerned, he said that improving the genetic merit of cows will have a direct and positive impact on a farm’s Carbon Footprint. He added that greenhouse gas emission levels are an indicator of the waste levels generated within a business.
“A higher merit cow can produce milk more efficiently,” he said.
“Improving milk yields per cow by 1,000L per lactation will reduce dry matter intakes per litre by between 9% and 12%. In turn, this will help reduce Carbon Footprint values by 9%.
“The key driver in this context is improved Food Conversion Ratios. In other words, higher merit cows are producing more milk per unit of feed input.
“This principle holds up in both high-concentrate feeding and grazing scenarios.”
Ross pointed out that feed losses are a fundamental contributor to Carbon Footprint values.
“Again, the higher the losses incurred the higher the predisposition to greenhouse gas production,” he said.
“Feed losses can occur both outside and inside the cow. For example, in the case of a sick cow, which has been withdrawn from her milking group, feed losses can be up to 100% with respect to the ration fed.
“As a matter of principle, feed efficiency levels will increase if rumen health is improved. Reducing a herd’s calving index is another way of reducing a dairy farm’s environmental impact.
“The principle is a very simple one: the less time that a cow spends in a pre-calving group, the more efficient she becomes in terms of producing milk.
“Replacement heifer rearing is another aspect of herd management that has a major impact on the environment. Bringing the age at first calving back from 27 months down to 24 will reduce Carbon Footprint values by 3%.”
Ross stressed the need for dairy farmers to address both the output and input sides of the production equation, when it comes to minimising the Carbon Footprint of their businesses.
“Protein is a key component of all dairy cow diets. This brings into focus the cost and environmental impact of including the likes of soya in rations,” he said.
“The benefits of including clover in both grazing and silage swards are immense. There is also significant scope to partially replace soya with forms of non-protein nitrogen in dairy diets.
“Such an approach will not reduce productivity. But it will help reduce Carbon Footprint levels.”