Abstract
Wereviewed specific literature for emissions of ammonia (NH3) and odours fromall stages of pig production together
with nitrogen (N) leaching from raising pigs outdoors. Emissions of NH3 decrease with decreases in the
crude protein (CP) content of pig diets, at all stages of manure management. The CPs of pig diets have been greatly
reduced by matching the CP content to the protein required at each stage of the animals' growth and by using
synthetic essential amino acids to minimise total CP intake. The CP contents of the dietary ingredients needed to
provide energy for the animals impose further limits to reductions in dietary CP. Housing systems have been
designed and evaluatedwhich offer potential for reducing NH3 emissions. However such designs may not be applicable
at all stages of the pigs' development and the carefulmanagement needed to ensure their effectiveworking
may be costly and difficult to implement on commercial farms. The factors behind odour emissions are less
well characterised. Reducing diet CP to 160 g CP kg−1 has been shown to reduce odour emissions but further
CP reductions may increase them. Some reductions in odour emissions from buildings can be achieved by careful
management of the ventilation rate but themost effectivemeasures to reduce emissions of NH3 and odours are to
cover slurry stores and to inject slurry into soil. Changes in the feeding and management of outdoor pigs mean
that N leaching losses may be up to 50% less than previously reported. No studies have been undertaken that
compare the N leached from pigs raised outdoors, versus that arising from the application of pig manure from
an equal number of housed pigs. As a precursor to any field study, current models could be used to provide a
first estimate of any systematic differences.
© 2013 Elsevier B.V. All rights reserved.
Original language | English |
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Pages (from-to) | 865 - 875 |
Number of pages | 11 |
Journal | Science of the Total Environment |
Volume | 470-471 |
Early online date | 6 Nov 2013 |
DOIs | |
Publication status | Print publication - 1 Feb 2014 |
Keywords
- Abatement
- Ammonia
- Diet
- Leaching
- Odour
- Pigs