A rolling programme of R and D trials focussing on sustainability and reducing environmental impact has found feeding a low carbon compound has little effect on milk production.

At James Stephen's Inch of Arnhall farm at Brechin – Harbro's dairy research alliance farm operating in partnership with the Glasgow Vet School – a low carbon treatment compound was formulated using the company's own rationing programme NutriONics and matched nutritionally to the diet and production targets of the cows. It was fed through two robots with a comparable compound from another feed manufacturer fed through another two robots.

The global warming potential of the low carbon compound was nearly half that of the control: GWP of compound one (low carbon) – 345 GWP100, GWP of compound two – 673 GWP100. The low carbon compound contained no soya or palm kernel and the competitor compound contained both. Although soya was still included in the TMR for both groups, the next stage in developing the ration on farm is to reduce its usage further.

At an average use of 4kg, with a milk yield of 35kg/hd/day, compound one is contributing 39g CO2e/kg of milk and compound two is contributing 77g CO2e/kg. Per 100 milking cows, the low carbon compound has the potential to lower the CO2e for the year for the dairy enterprise by 47,888kgCO2e.

This would be equal to taking 21 cars off the road for a year or six flights around the world.

The results showed there were no production differences between the two groups.

Maimie Sloan, Harbro dairy technical nutritionist commented: “This is really exciting news for dairy producers. Many parts of the supply chain, both milk processors as well as retailers, are challenging their producers to reduce their environmental footprint, with some rewarding farmers that can prove they’re reducing carbon on farm.

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"The results show that farmers can now feed a low carbon dairy compound without negatively affecting performance. With the low carbon dairy compound featured in the trial carrying no additional cost compared to the control diet, it makes financial sense to farmers to switch, especially if their milk contract requires it."

Although it wasn’t measured within the parameters of the trial, the Stephens at Inch of Arnhall are long standing customers of the methane reducing additive, Rumitech which they feed in their powder dairy minerals. Rumitech can be fed as part of a flexible feeding system, and included in a mineral, compound or blend to complement a farm’s available raw materials or feeding system. It has been assured by the Carbon Trust to reduce methane emissions and some parts of the supply chain give automatic credit for correctly feeding Rumitech in carbon audits.

Nutrition is just one pillar of the approach to sustainability with management and health also key variables for sustainable milk production. A new rationing programme designed to meet the performance and health requirements of the herd has also had financial benefits for the farmer as well as the environment with the creation of more efficient milk.

At Inch of Arnhall, Caitlin Palmer, Harbro's R&D co-ordinator has been tracking performance on a weekly basis for the past 12 months, keeping a close eye a number of KPIs using both internal performance and benchmark monitoring programmes as well as looking at Interherd+ data and analysing feeding patterns from the Keenan InTouch system on farm.

Caitlin said: “The insight the data gives us is invaluable; it enables us to identify even slight fluctuations in performance that could otherwise go unnoticed and we’re then able to respond accordingly. This means rations are matched as closely to the biological requirements of the cows as possible, which not only has a positive effect on performance, but it also maximises resource and nutrient efficiency, minimising waste and optimising feed efficiency which is essential for farmers at the moment with the increasing cost of raw materials and all major inputs.”