A two-year project in which Cornish and Breton dairy farmers worked together on low carbon practices has come to an end.

The Agriculture bas Carbone for Dairy farms (ABCD) project looked at practices including cow diet changes, multi-species grassland and agroforestry, with the former having potential to reduce carbon footprints by 10 per cent alone.

“The first part of the project aimed to reduce dairy farms’ carbon footprint by 10 per cent,” said Gaid Carval, economic growth officer at Cornwall Council.

“It looked at cows’ diets and how to formulate them to reduce carbon footprint. In Cornwall, the trials were led by Duchy College at its Future Farm.”

The team carried out the trials in October 2022 and January/February 2023 with cows from a 196-head herd, block-calved from August to October. They used two groups of 62 cows in the trial. These were balanced by parity and predicted milk yield (butterfat and protein), were milked twice a day and fed five times a day using an automated robotic feeding system (Trioliet).

Concentrate blends were formulated with or without soya, with equivalent levels of crude protein (22.3 per cent), metabolisable energy (14.8MJ ME/kg) and fibre (5.11 per cent). Where soya was excluded from blends, rapeseed meal was used instead.

“Milk production, milk quality and body condition scores were unaffected with a ration containing no soyabean meal, compared with a diet containing soya,” said research and programme manager at Duchy College, Paul Ward.

“Using this soyabean meal-free ration was estimated to deliver a significant reduction of 80g/litre of milk CO2e (8.6 per cent) in carbon footprint.

“Assuming the herd was making progress on other measures like improved fertility, first calving optimisation, better health and use of home-grown protein, total carbon footprint would fall by 10 per cent,” said Mr Ward. But longer term research is needed to confirm the estimates.

The second aspect of the project involved supporting producers in adopting new low carbon practices on farm.

“Duchy College led this in Cornwall, holding meetings with farmers,” said Ms Carval. “Saputo Dairy, Trewithen Dairy and Rodda’s Dairy were also involved and useful in helping us to reach farmers.

“We were aiming to reach as many farms as possible and support them in transitioning to low carbon practices,” she added. A survey carried out by ABCD early in the project revealed that ‘how to complete a carbon footprint’ was the most popular training requirement topic, in relation to carbon management (56 per cent). Manure and fertiliser management came second (51 per cent) and soil management, third (43 per cent).

In a further knowledge exchange activity, 15 farmers from Cornwall visited farms in Brittany in August 2022, and 12 French farmers came to Cornwall in June 2022.

A few ideas concerning low carbon practices were shared during the Cornwall/French exchange visits such as the installation of small anaerobic digestor plants on small farms without huge cost which is enabling French farmers to produce some of their energy requirements.

As the project ends, Ms Carval reflected on its achievements. “It has led to good trial results. Also, a lot of discussions and opportunities to try new practices on farms. There have also been opportunities to build links, not only between farmers, but also farming researchers in France and the UK,” she noted.

The Agriculture bas Carbone for Dairy farms (ABCD) project, an Interreg project co-funded by the EU, included Finistère Council, the Chamber of Agriculture of Brittany and Cornwall Council – which partnered with Duchy College to deliver the work. It was funded by the European Regional Development Fund (ERDF), to the sum of €500,000 (£440,000), with Cornwall Council receiving €160,000 (£140,600) from the EU fund. The project ran from March 2021 to March 2023.