Submitted by on Thu, 11/10/2018 - 15:56 Horizontal tabsSummaryAim of Measure: Lowering crude protein content of animal diets can decrease NH3 loss.Nitrogen Species: Ammonia emissions (NH3)Climatic Zone: Semi-aridTemperateTropicalAridGeographic Region: GlobalSector: Agriculture (livestock)Sector Category: Livestock Feeding Measure DescriptionMeasure overview: Gaseous N losses from livestock production originate from the faeces (dung) and urine excreted by the livestock. The animal feed composition and the feed management has a strong influence on animal performance but also on the composition of the dung and urine, hence the emissions of NH3. Low-protein animal feeding is one of the most cost-effective and strategic ways of reducing NH3 emissions. For each per cent (absolute value) decrease in protein content of the animal feed, NH3 emissions from animal housing, manure storage and the application of animal manure to land are decreased by 5%–15%, depending also on the pH of the urine and dung. Low-protein animal feeding also decreases N2O emissions, and increases the efficiency of N use in animal production.How to implement the measure: Lowering crude protein of poultry diets is an effective and category 1 strategy for decreasing NH3 loss. The following guidelines hold:For poultry, the potential for reducing N excretion through feeding measures is more limited than for pigs because the conversion efficiency currently achieved on average is already high and the variability within a flock of birds is greater. A crude protein reduction of 1%–2% may be achieved depending on the species and the current starting point. The resulting range of dietary crude protein contents is reported in the table below. The values in the table are indicative target levels, which may need to be adapted to local conditions. Further applied nutrition research is currently being carried out in EU member States and North America and this may support further possible reductions in the future. A reduction of the crude protein content by 1%–2% is a category 1 measure for growers and finishers.Indicative target crude protein levels in feed for poultrySpeciesPhasescrude protein content (%)aChicken, broilersStarter20–22 Grower19–21 Finisher18–20Chicken, layers18–40 weeks15.5–6.5 40+ weeks14.5–15.5Turkeys< 4 weeks24–27 5–8 weeks22–24 9–12 weeks19–21 13+ weeks16–19 16+ weeks14–17Source: Based on European Commission, 2003.a With adequately balanced and optimal amino acid supply. The values presented here can be considered as “medium to high ambition level” (see annex II for a further specification of target crude protein levels).Co-benefits and trade offs: Cost Effective: Low-protein animal feeding is one of the most cost-effective and strategic ways of reducing NH3 emissions. Animal Welfare: As long as the requirements for all amino acids are met, there are no animal health and animal welfare implications of implementing this measure. Challenges: Complexity of phase feeding: The disadvantages of moving from one feed to a phase feeding system includes greater complexity in ordering feed and the potential need to install additional feed bins on the farm. However, with increased pressures on profitability, these disadvantages must be weighed against the benefits of improved animal performance and profitability. Measure EfficiencyIndicator for the efficiency of the measure: Nitrogen SpeciesAmmonia(NH3) Ammonium Nitrate (NH4NO3)Nitrogen Dioxide (NO2)Nitrous Oxide (N2O)NOxNrTotal N % of Reduction5-15%------- Reference system: The abatement strategies described are not defined and assessed against a uniform reference (or unabated or baseline) feeding strategy, because these reference feeding strategies are different for different countries and between animals. Finanacial ImplicationsOverview of cost: In general, the economic costs range from -€2 to +€2 per kilogram NH3-N saved (in UNECE countries), i.e., there are potential net gains and potential net costs. The economic cost of animal feeding strategies to lower the NH3 volatilization potential of the animal excrements through adjusting the crude protein content depends on the initial animal feed composition and on the prices of the feed ingredients on the market. Commonly, the economic costs increase when the target for lowering the NH3 volatilization potential increases. The increasing marginal costs relate in part to the cost of synthetic amino acids supplementation relative to using soybeans. The costs of amino acids supplementation tend to go down. The cost of supplementation of amino acids increases when the target protein content in the animal feed is lowered. Financial Implications table definitions: Cost savings and production benefits ($)Capital costs of implementing this measure ($)Operational costs of implementing this measure ($) -2 euros to +2 euros per kilogram of NH3-N saved (in UNECE countries). -2 euros to +2 euros per kilogram of NH3-N saved (in UNECE countries). -2 euros to +2 euros per kilogram of NH3-N saved (in UNECE countries). Refs and Further InfoReferences: Bittman, S. Dedina, M. Howard, C.M. Oenema, O. Sutton, M.A. (eds) (2014) Options for Ammonia Mitigation Guidance from the UNECE Task Force on Reactive Nitrogen. Centre of Ecology and Hydrology, Edinburgh, UK. European Commission (2003). Reference Document on Best Available Techniques for Intensive Rearing of Poultry and Pigs. Integrated Pollution Prevention and Control (IPPC). July 2003. Available from http://eippcb.jrc.es/reference/irpp.html.
