Another Life: Belches, farts and slurry – milk’s carbon footprint problem

Methane from cows makes up more than half of the greenhouse gases arising from milk production. With Ireland’s dairy herd set to grow rapidly , manipulating their diet is the most promising control

Cattle are scarce on a hillside full of sheep, so I pause on the boreen to exchange gazes with a little suckler herd, so clean and amiable in their tawny hides against the blue of the sea. That’s my quirky slant on such beasts, just as I fancy the sculptural shapes they make when lying down, or relish Eamon Grennan’s line about “the way a torn tuft of grassblades, stringy buttercup and clover sway-dangles towards a cow’s mouth, the mild teeth taking it in . . .”

It’s only when the stench of slurry, sprayed on mown silage meadows, taints the summer breeze that I’m reminded of the downside of the dairy country beyond the hill . Ireland’s 1.14 million cows plod patiently home to the parlour, their swollen udders swinging ever closer to the ground. Milk production will peak late this year, after May’s chilly check to grass growth. But, at 5,000 litres per cow, it should pass the 5.4 billion litres of a sunnier 2014. With EU milk quotas gone, we surge on to the national target of half as much milk again by 2020, and beyond to the many thousands more cows munching the meadows for China.

I was intrigued, therefore, by the outrage of George Monbiot, the Guardian's combative columnist, at his paper's distribution of a children's book, The Tale of City Sue. Described by the Guardian as a "tale from the meadow of imagination", it tells of an Irish farm where a "friendly Friesian family" enjoy an idyllic life with a farmer who brings party hats to their birthdays and plays a violin in the milking shed. This happy herd is joined by a snooty indoor cow who likes to stay in the dry and eat rations. She is coaxed into agreeing that the grass outside is really best.

Monbiot read this, he wrote, to his three-year-old, then came upon the sponsoring logo of Kerrygold butter, much to his ethical disgust at spinning fibs to children . His reproaches to the Guardian, the book's author, Jeanne Willis, and Kerrygold's UK parent company, Adams Foods, led him to challenge Kerrygold's website boast of working "with small co-operative farms where small herds are free to graze on lush Irish meadows".

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Violin-playing farmers

The average Irish herd size is, indeed, about 60 cows, but Monbiot discovered last summer’s “open day on large herd management”, arranged by

Teagasc

at a farm in east Cork. It milks 820 cows, yields 6,000 litres from each, and uses barley, soya and home-grown maize along with the grass. The event attracted some 3,000 milk producers. As Monbiot concluded, small, violin-playing farms may not really be the model of Ireland’s future dairying.

The likely environmental effects of the 2020 dairy target have met with a fairly sanguine response from Teagasc’s researchers, and analysis by consultants. Although an extra 300,000 cows seem a lot to bring into the landscape, this is seen as largely achievable by a switch from beef cattle to milk within existing farms.

A big milk increase beyond 2020, however, will need a lot more cows, which means even higher emissions of greenhouse gases such as methane in their belches, farts and slurry. If Irish farming is to keep its favourable carbon footprint by comparison with most EU states,“mitigation” becomes the keyword.

Methane from cows amounts to more than half of the total greenhouse gases arising from milk production. Manipulating their diet is the most promising control, and Teagasc at Moorepark has studied which cultivars and mixtures of ryegrass and clover minimise the methane. Genetic selection may also find cows whose gut microbes are better behaved.

Forestry drive

Teagasc’s 28-strong working group on mitigating greenhouse-gas emissions from Irish agriculture made a lengthy interim report in March. It called for a big new drive for forestry, to lock up increased carbon from farming. Current planting, it pointed out, is below what is needed simply to keep up with emissions. Increasing it from 8,000 to 20,000 hectares a year, it urged, could halve the national agricultural contribution to the atmosphere, especially if the timber goes into construction.

But where is the new forestry land to come from? At the moment, says the group, expansion depends too much on farmers converting from agriculture to tree plantation. Forestry is, rather, “an excellent land use option for much of the land that is marginal to economic agriculture” – in other words, most of small-farm Ireland. It recognises that “conservation constraints may limit or preclude forestry expansion or land use change. Where competing environmental objectives exist, there may be merit in considering strategies that optimise the totality of environmental benefits.”

Is this a recommended comeback for blocks of new Coillte conifers, and surrender of protected habitats and landscapes? This should be good for many arguments to come.