Effects of Oregano Essential Oil on IgA+, IgG+, and IgM+ Cells in the Jejunum of Castrated Holstein Bulls - Qiyan Liu; Wangdong Zhang; Baoshan Wang; Jinping Shi; Pengjia He; Li Jia; Yongliang Huang; Meiling Xu; Yue Ma; Qiang Cheng; Zhaomin Lei (Animals, 2023)