How can UK dairy farmers reduce their emissions?
The most effective way to reduce GHG emissions is to improve the overall efficiency of dairy farms, which has the added benefit of reducing costs as well as the carbon footprint.
Husbandry methods, such as reducing herd replacement rate, calving heifers when younger, genetic selection for increased milk yield and fertility rates, and improving housing systems, grassland management and grazing systems, can all reduce the GHG emission intensity.
Dairy cow feeding
The way that dairy cattle are fed can have a large impact on the carbon footprint. Methane production is an inherent part of rumination (digestion), but the quantity of methane produced per litre of milk can be reduced through improving the concentrate and forage balance of the diet. This can be done by optimising the balance of grass and maize silage, adopting phase-feeding by milk yield, increasing the proportion of fat and oil in the diet, using high sugar content grasses (ryegrass), or using feed additives such as 3NOP (3-nitrooxypropanol), probiotics or nitrate in rations.
The source of feed is also very important: diets containing soya have very high embedded emissions associated with the land-use change (deforestation) and transportation of the feed. Many farmers are often reluctant to move away from soya as it is such a good protein source for high yielding dairy cows, but alternatives with a lower carbon footprint, such as rumen-protected rapeseed meal, are starting to be widely used with no compromise to productivity.