   Genetic selection for slower growth\                                             \[[@B000-animals-00-00000],[@B000-animals-00-00000]\]                                                                                         Dermatitis                                                                                                   Floor and facilities quality (hardness, wet, dirt)                                                                                                       Reduce feed\                                                                                                                                                                                                                                                                                                                                                                                                                                    Improve 