Dairy farmers in the UK are facing the double-edged challenge of meeting environmental sustainability requirements while also managing their farm in a way that ensures the long-term viability of the business.
The Farm of the Future, Decarbonising UK Dairy Production sector paper identified five areas of focus for dairy production to improve sustainability. These include driving yield per rumen, health and welfare, enhanced breeding, managing nitrogen on-farm and novel technologies. The ways in which they provide opportunities to produce milk more efficiently and support farm business sustainability are explained below.
1. Driving yield per rumen
A more efficient cow that can produce milk with fewer inputs is a more sustainable cow.
Farmers face increasing focus on the damaging environmental impact of methane and nitrous oxide on climate change. By making each cow, or each rumen, as efficient as possible, milk production can be maximised at the lowest emissions level or environmental cost.
For example, a dairy cow that has increased its annual milk yield by 500 litres to 7,000 litres through a mix of better breeding, high quality forage and better health management, will have broadly the same environmental impact as the same cow producing 6,500 litres.
2. Health and welfare
Overall, there is a direct correlation between the farms with the healthiest cows and those with a lower carbon footprint per kg of milk. In other words, healthy cows convert feed to milk more efficiently and release less methane. Putting animal welfare front and centre of dairy farming is good for the cow and good for the environment.
3. Enhanced breeding
The benefit of genetic gain for the dairy cow is not new to UK farmers, but science in this area has developed hugely in recent years with the introduction of genomics and sexed semen and is now being harnessed to drive environmental improvements on-farm.
Genetic indexes can help farmers breed more environmentally friendly cows. For example, EnviroCow reflects the important role genetics and breeding play in improving the environmental efficiency of milk production. It incorporates cow lifespan, milk production, fertility and the Feed Advantage Index to enable cows to be bred based on their environmental credentials.
Integrated, farm-wide breeding strategies, including genomic testing to help develop key sustainability traits (production, health, longevity, FCE) are being developed. Advances in semen sexing technology have seen significant improvements in conception rates, leading to faster generational intervals and better dairy-beef integration. Selection for high milk solids has also helped to improve FCE.
Rumen methane production can be also manipulated by genetic selection, helping reduce the dairy sector’s emissions footprint. Increased genomic testing has enabled the identification of a herd’s most efficient and therefore most sustainable cows to breed from. Farmers can now identify cows that produce higher levels of milk solids with the same level of input, enabling them to produce the same or more milk solids with fewer cows.
4. Managing nitrogen on-farm
Better management and use of nitrogen will help reduce greenhouse gas (GHG) emissions from dairy farms.
Assessing a farm’s nitrogen balance by measuring the nitrogen introduced onto the farm through feeds, fertiliser, stock and manures, compared to the nitrogen leaving the farm through milk and outputs is crucial. The difference between the two figures effectively represents the nitrogen unaccounted for, or most likely, lost to the environment, either to air or into the ground or water. This nitrogen balance is a measure of the efficiency of nutrient and input use on the individual farm.
Reliance on manufactured nitrogen fertiliser is a major driver of GHG emissions. Improved management of slurry and manures will reduce ammonia/nitrogen losses, as will improved technologies for spreading, such as injection. Moving away from reliance on fossil-based fertilisers to feed grass pastures to inclusion of a higher proportion of nitrogen-fixing legumes will reduce reliance on synthetic nitrogen without reducing feed quality.
Dairy farmers are also changing how they manage the soil, looking at cropping profiles and better slurry management to help reduce losses. Covering of slurry storage, on-site digestion of manures and residues, plus low emission spreading techniques with targeted application will all have an impact. In addition, reducing the protein levels in cow rations will avoid wasting nitrogen.
5. Novel technologies
The industry is trialling and adopting a range of practices, products and procedures that can help reduce the industry’s environmental footprint. These technologies can reduce waste and emissions from dairy farming activity and increase efficiencies at a farm and milk processing level.
Precision dairy farming technology needs to be well implemented to ensure farmers can access data to help manage their herd. Interpretation of the data is key, and it can be challenging to identify the best management changes suited to individual herds. Precision systems include intelligent collars, ruminant bolus devices and in-parlour systems that improve monitoring of herd performance. Potential technology developments include:
- Methane-reducing additives in feed
- More targeted application of slurries and bought-in fertilisers
- Remote monitoring of cattle lameness
- Acidification of slurry to minimise ammonia emissions
- Replacement of diesel with biofuels (including biomethane produced on farm)
- Possible supply of biogas (or biomethane) from farms to their milk processors
- On farm processing of milk for local sale – thereby reducing transport emissions
- Increased use of robotics (already well established for milking on some farms) and autonomous vehicles to reduce feed wastage and manage slurry
In the dairy industry, milk processors are increasingly taking action to reduce their environmental impact. As on-farm emissions account for most of their scope three emissions, the emphasis is being put on meeting carbon reduction targets at the farm level. For more information on solutions for dairy farming visit the Decarbonising UK Dairy Production sector paper.