Volume 165, July 2014, Pages 138–146
Highlights
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- N excreted was 6.0 and 4.2 kg N pig−1 during winter and summer, respectively.
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- N-losses of N excreted were the same (26–27%) during winter and summer.
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- N emitted from organic pigs was 3–4 times greater than that from non-organic pigs.
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- Larger fouled areas, less optimized feed and higher usage explained the differences.
Abstract
The
effects of two housing systems (deep litter and straw-flow), with and
without access to pasture during the summer period, were studied in an
organic growing–finishing pig herd. Pen hygiene studies, N, P and K
budgets and estimations of nitrogen emission were made for two batches
(8 pens/batch and 16 pigs/pen) one during the winter period and one
during the summer period. It was concluded that there were no
significant differences in overall pen hygiene between the housing
systems. During the growing period in the summer, the pen hygiene on the
outdoor concrete area was significantly better (P<0.05) when the pigs had access to pasture. In addition, the total pen hygiene (indoors+concrete area outdoors) tended (P=0.09)
to be cleaner with access to pasture during the summer period. The
N-losses of the amount of N excreted were the same (26–27%) during the
winter period as during the summer period. The amount of N excreted was
on average 6.0 kg N per pig during the winter, and 4.2 kg N per pig
during the summer; this was equivalent to an N-emission of 1.5–1.6 kg
N/pig during winter and 1.1–1.2 kg N/pig during summer. The difference
was mainly due to a higher feed consumption and more straw usage during
the winter. In comparison to the calculated N-emissions from a
non-organic pig, this was approximately 3–4 times greater. In the
present study, a 10% larger feed usage explained the differences in
N-emission by a factor of 1.2, a 15% higher crude protein level
explained the differences by a factor of 1.3 and finally a larger fouled
area explained the differences by a factor of 2.3. Differences in
temperature and airflow were not taken into account in these
calculations.
Keywords
- Organic;
- Pig production;
- N, P and K budgets;
- N-emission;
- Housing systems
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