The study compared different ways of managing pig manure in pig farming to see which has the least impact on the environment. They looked at three methods: using pig manure as fertiliser, treating manure to make fertilisers, and a mix of both. The results showed that making fertilisers from treated manure had the biggest environmental impact. Using manure directly as fertiliser had a smaller impact, and combining both methods had an even smaller impact. So, using manure as fertiliser seems to be the best choice for the environment. The study suggests a system where pig manure is used as fertiliser directly and also processed into mineral-organic fertiliser, which could be a good environmental option.