Some kids do struggle. Don't allow them to name the animals or give them nicknames or call them anything cutesy. If your kids do chores around the livestock, then make sure to rotate them out so no one becomes too familiar with the cows, chickens, or other creatures. That helps them from becoming too fond. However, sometimes they just don't get over it. In those instances it's best to keep the child away from the animals. Those children should do house chores instead and will probably need to visit someone else when it's time for slaughter.