Pig houses – Less proteins, less ammonia
The Netherlands Researchers at Wageningen University and Research Centre have researched the effects on the emissions from pig houses of a low protein diet with and without the partial replacement of calcium carbonate by calcium chloride. The studies were carried out at four commercial pig farms.
Emissions were measured in four units with growing-finishing pigs. In two of these pig units the control diet was fed. In the other two units of each farm a low emission diet was fed. At each farm one low emission diet was fed: Low protein with or low protein without calcium chloride. The same diet was fed during one year.
The effect on ammonia emission of lowering the protein content of the feed was of the same magnitude as in earlier studies. Per 10 g reduction of crude protein content, the ammonia emission decreased 14%. Odour emission was decreased by 19% by the low protein diet compared with the control diet.
Diet did not have an effect on methane emission. From the economic evaluation it was concluded that a low protein diet can be cost efficacious in farms that manage to apply this diet without reducing pig growth and without increasing feed conversion rate.
