UK Agricultural Policy Post-Brexit Editor: Will Melling Writers: Bence Borbely, Trevor Chow, Tom Nott, Yang Zuo
of feed intake.54 The proposed measures for tackling enteric fermentation include altering ruminants’ feed composition, applying artificial feed additives, improving breeding practices and encouraging appropriate grazing management practices. The discharge of GHG-s from manure occurs as follows: Methane is naturally released from the anaerobic decomposition of organic material. In addition, substantial amounts of nitrous oxide (N2O) are produced during the storage and treatment of the animal waste. Nitrous oxide is produced from the combined nitrification-denitrification process that occurs on the nitrogen in manure. The majority of nitrogen in manure is in ammonia (NH3) form. Nitrification occurs aerobically and converts this ammonia into nitrate, while denitrification occurs anaerobically, and converts the nitrate to N2O.55
2.2.1 Enteric Fermentation The enteric fermentation of cattle and sheep is the single gravest threat to UK agricultural climate sustainability. Enteric methane excretion accounts for roughly 75 per cent of such emissions in British agriculture,56 with ruminants such as cattle and sheep in the forefront. Gas production from cattle farming makes up about 60 per cent of total methane emissions on the countryside, with sheep taking an additional 14 per cent, leaving a mere 1 per cent share for pigs, poultry and others.
Feed Composition Altering the feed composition of cattle and sheep aims to reduce the emissions intensity of livestock while also enhancing feed efficiency at the same time. About 10% of a cow’s energy intake is typically lost through the enteric fermentation process,57 which means that farmers are also economically incentivized in the long-run to increase animal productivity by minimizing this digestive deficiency in utilizing feed intake. Besides being a no-regret measure with no trade-offs but only benefits from both environmental and economic perspective, the optimisation of digestibility delivers positive results instantaneously and does not require great financial investment. According to the findings of the UN Food and Agriculture Organisation in Argentina, the strategic supplementation of adult female cows for a period of 90 days with cottonseed and sunflower meal reduced enteric methane kg CH4
54
Department for Food, Environment & Rural Affairs, Agricultural Statistics and Climate Change [6th Edition, July 2015] https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/476879/agricli mate-6edition-13nov15.pdf 55 Paul Jun, Michael Gibbs, Kathryn Gaffney, ‘CH4 and N2O Emissions from Livestock Manure’ [1996] https://www.ipccnggip.iges.or.jp/public/gp/bgp/4_2_CH4_and_N2O_Livestock_Manure.pdf 56 National Atmospheric Emissions Inventory, Pollutant Information: Methane https://naei.beis.gov.uk/overview/pollutants?pollutant_id=3 57 Food and Agriculture Organization of the United Nations (FAO), Reducing Enteric Methane for Improving Food Security and Livelihoods [2016] https://www.ccacoalition.org/en/activity/entericfermentation#:~:text=Available%20measures%20to%20reduce%20methane,and%3B%20improving%20perfor mance%20through%20breeding
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