Good for cows, good for the planet: reducing dairy's carbon footprint
Our research has transformed practices in the UK animal feed industry and is helping address the impact of dairy farming on greenhouse gas emissions.
By establishing the nutritional value of cost-effective, alternative and sustainable sources of protein, we have helped to lower emissions from dairy herds and reduce the carbon footprint from imports - the UK annually imports around 3.53 million tonnes of soya bean meal from South America and other countries. Most is used in animal feed for chickens and pigs, but about 20% is used in cattle feed.
Soya production is linked to deforestation in South America, and pressure from consumers and retailers, together with rising import costs, have encouraged the UK animal feed industry to seek alternative protein sources.
Our research explored the potential for co-product feeds - secondary products produced from arable crop and food processing that would not otherwise be used in the food chain - to be incorporated in dairy cow diets.
Co-products, such as dried distillers grains with solubles (DDGS) and rapeseed meal offer potentially cost-effective and sustainable alternative protein sources to soya.
However, the nutritional value of these alternative protein sources was uncertain. Our research is helping industry maximise the potential of these high-performing animal feeds and farmers to correctly incorporate them in cows’ diets.
A key project, funded under the UK government’s Department for Environment, Food & Rural Affairs (DEFRA) Sustainable Livestock Production LINK Programme, sought to evaluate the benefits of feeding livestock co-products from the UK bioethanol industry.
The University of Nottingham, which is home to the Centre for Innovation Excellence in Livestock’s Centre for Dairy Science Innovation, worked with a consortium of 25 partners, colleagues from the University of Manchester, Scotland’s Rural College, Marks and Spencer and industry partners from all sectors of the UK bioethanol, livestock and arable industries.
This rapeseed meal is a protein source that is resistant to degradation in the cow’s rumen (first stomach) and provides essential amino acids - rumen bypass protein - as it passes into the lower gastrointestinal tract. The trial provided comprehensive nutritional values for NovaPro and feeding studies demonstrated that cows yielded more milk (1.7 litres per cow per day) when fed on NovaPro than when fed on soya bean meal, which was specifically attributed to the superior amino acid profile of rapeseed compared with soya.
We provided comprehensive nutritional values for UK and EU wheat-DDGS and demonstrated that diets with high proportions of co-product could deliver high milk yields while providing environmental benefits from lower emissions.
We provided evidence of the nutritive potential of co-product feeds in dairy cow diets, demonstrating that they are viable alternatives to soya as protein sources and increasing industry confidence to replace soya with domestic co-products as the main protein source in dairy cow feed.
Nutritional composition values determined by our research for wheat DDGS (w-DDGS) and NovaPro are now used throughout the dairy feed industry.
"By influencing UK policy and providing our dairy feed industry with cost-effective, greener solutions, we are demonstrating the power of innovative research in securing a sustainable future."
It is gratifying that our evidence-based science is helping to address a significant factor in global warming. By influencing UK policy and providing our dairy feed industry with cost-effective, greener solutions, we are demonstrating the power of innovation in securing a sustainable future.
Phil Garnsworthy is Professor of Dairy Science in the School of Biosciences