A.25% B.40% C.60%
A.0.5—1.0 B.1.5—2.0 C.3.0—3.5
A.每天檢查每頭豬只 B.及時(shí)處理對(duì)醫(yī)治無(wú)效的豬只,以切斷病的散發(fā) C.A、B兩項(xiàng)全對(duì)