It is because you are a «guest» in their country and need to be respectful of local customs. (religion.blogs.cnn.com)
So again, 11 months later, my suggestion is that you keep with local customs in your contracts and see an attorney to at least bless them with legal water. (biggerpockets.com)
They can be made of beef, chicken, pork, as well as lamb, depending on local custom and individual tastes. (fieryfoodscentral.com)