The problem isn’t general meat production, it’s with Aid al-Adha/el-Kebir and the sacrifice of the mutton/goat. Traditionally, each family killed the animal at home, but now in Belgium and France, state-controlled slaughterhouses must be used, by law, so as to guarantee it is killed the most humanely possible. Both Belgium and France open up a number of temporary slaughterhouses around Aid for this reason, to make sure Muslim families have a place close enough they can go to, but a lot of people say there aren’t enough (and in Belgium they started getting rid of them, IIRC), and many families prefer to continue killing the animal at home, for traditions sake.