Diet composition and modified climatic properties - means to reduce ammonia emission in fattening pig units

摘要

In connection with reconstruction and new buildings a number of technological methods have been approved to reduce ammonia emission from livestock buildings. But methods applicable for reducing emission from existing buildings are highly needed. A number of methods aimed to reduce emission also in existing buildings were studied under controlled conditions in a Gas Emission and Climate laboratory equipped with two experimental sections each designed for 40 fattening pigs (25-100 kg BW). Experiments were conducted on a group of fattening pigs allocated to either a diet with 80 ppm Micro-Aid~(R) (a juice extract from the Yucca Schidigera plant) or a pure cereal-soybean meal-based diet (control). The average ammonia emission per produced kg pork was 15-20 percent lower from the pigs fed with Micro-Aid~(R) mixed into the diet than from a control group fed with a diet without Micro Aid~(R). Secondly experiments were carried on a group of fattening pigs allocated to either a diet with 15 percent pelleted sugar beet pulp or a pure cereal-soybean meal-based diet (control). Results showed a negligible reduction in ammonia emission per produced pig fed with sugar beet pulp diet. One of the reasons was reduced daily gain and heavily polluted floor surface in the section containing the pigs fed with the sugar beet pulps. Finally experiments aimed to quantify the effect on ammonia emission due to reduction of the indoor temperature was conducted. The average temperature in the experimental section was 5 deg C and in the control section 15 deg C. A shield was designed generating a two-climate system maintaining acceptable thermal conditions for the pigs in the cool section. The ammonia emission from the cool section was 40-50 percent lower during winter conditions compared to the control section. It was concluded that it is possible to reduce ammonia emission from existing buildings using Micro Aid~(R) mixed into the diet or through a building design allowing low indoor room and/or slurry temperature. No effect was found due to use of Sugar Beet pulps in the diet.