The present invention relates to variants of porcine granulocyte colony stimulating factor (pG-CSF). The pG-CSF variants are useful in treating preventing or reducing the incidence of bacterial infections in swine. Methods of treating swine are disclosed.本發明係關於豬粒細胞群落刺激因子(pG-CSF)之變異體。該等pG-CSF變異體可用於治療、預防或降低豬中細菌感染之發生率。揭示治療豬之方法。