A study by the University of Nottingham, United Kingdom, in collaboration with Wynnstay, has shown that dairy cows can thrive on a soya-free diet, leading to increased milk production and reduced farm emissions. Conducted on a herd of 400 Holstein Friesians, the research recorded a rise in milk yield while cutting carbon emissions and improving protein efficiency.
A research study conducted by the University of Nottingham in partnership with Wynnstay, a UK-based agricultural supply company, has revealed that dairy cows can thrive on a soya-free diet while boosting milk production and reducing farm emissions. The study, which focused on a herd of 400 Holstein Friesians, recorded significant improvements in milk yield and environmental impact.
Soya-Free Diet Leads to Higher Milk Production
According to the study, cows on the new diet produced 4.8 kilograms more milk per cow compared to 2023 figures. Additionally, milk urea levels dropped from 249 mg per liter to 176 mg per liter, indicating improved protein efficiency. The research aligns with the University of Nottingham’s goal of reducing the carbon footprint in dairy farming and meeting sustainability expectations set by milk buyers.
The diet, which was implemented in March 2024, replaced soya with alternative ingredients such as rumen-protected amino acids, protected rapeseed meal, and rumen energy sources. Crude protein content was reduced from 17.5% to 16.7%, while starch content increased from 18% to 22.5%, leading to better milk yield and fertility rates.
Lower Carbon Emissions and Improved Forage Use
The study also highlighted that transitioning to a 100% soya-free diet resulted in a 14% increase in forage intake, which helped enhance milk output from homegrown forage. This dietary adjustment led to over a 10% reduction in CO2 equivalent (CO2e) emissions per kilogram of milk. The environmental impact per portion of milk dropped from 37 kg CO2e to 21 kg CO2e, marking a significant step toward sustainable dairy farming.
We’ve proven that cows can thrive without soya in their diet, which is a huge step forward in reducing the carbon footprint of dairy farming, Our approach not only benefits the environment but also improves farm profitability by increasing milk production from homegrown forage.”
David Howard, head of dairy at Wynnstay
Future Prospects and Industry Impact
Looking ahead, researchers aim to achieve over 5,000 kilograms of milk from forage per cow. Plans are also in place to optimize feeding strategies for first-lactation heifers, ensuring better growth and efficiency.
We have only seen positive outcomes—higher milk yields, increased forage intake, and lower urea levels. As a high-production commercial herd operating within a university, we strive to lead in dairy innovation. I just wish we had made this change sooner.”
Nigel Armstrong, the dairy herd manager at the University of Nottingham
The study’s findings present an opportunity for the dairy sector to shift towards more sustainable feeding practices, benefiting both farmers and the environment.
