Excreting behaviour of pigs from organic housing systems in relation to ammonia emission

Summary

The objective of this study was to establish a pattern of excreting behaviour of pigs in relation to ammonia emission and to predict the ammonia emission rates from clean and fouled with excretions areas.
The study involved 3 organic pig farms in which the housing systems included straw pens inside and a paved yard outside.Two pens with fattening pigs were chosen on each farm and measurements of excreting behaviour and ammonia emission were made at two stages in the fattening period, at approximately 45 and 80 kg of body weight. Behaviour was observed with video cameras at two consecutive days for 24 hours. From video recordings urinations and defecations, including the corresponding times, were noted. Diagrams of the excretion activity pattern during the day for every weight class and every farm were made. From the figures of the frequency of urinations during the day it was clear, that in all the tree farms there were two excretion peaks – one in the morning and one in the afternoon-evening hours. Clean areas inside emitted 1.9 g ammonia.day-1m-2 and clean areas ouside – 2.7 gday-1m-2. Inside polluted areas had a higher emission than the polluted areas on the outside yard – 13.3 gday-1m-2 vs 11.4 gday-1m-2, resp.