硫酸头孢喹肟乳房(干乳期)注入剂在奶牛乳汁中的残留消除研究

Residual Study of Cefquinome Sulfate Intramammary Infusion(Dry Period) in Milk

建立了牛奶中硫酸头孢喹肟残留超高效液相色谱-串联质谱检测方法(UPLC-MS/MS)。选取18头刚进入干乳期的健康奶牛,随机分为6个组,分别于预产期前的42、35、28、21、14和7 d进行乳房注入硫酸头孢喹肟乳房注入剂(3 g∶150 mg/支),只用药一次,产犊后采集奶样。结果表明:预产期前7 d给药,奶牛产犊72 h后采集的奶样中头孢喹肟残留量降至MRL(20μg/kg)附近;预产期前14 d和21 d给药,奶牛产犊12 h后采集的奶样中头孢喹肟残留量降至MRL以下,均低于检测限;预产期前28、35和42 d给药,所有采集奶样的头孢喹肟残留量均低于检测限。建议在预产期前7、14和21 d给药硫酸头孢喹肟乳房注入剂的弃奶期分别为产犊后5、1和0 d。

The high performance liquid chromatography and tandem mass spectrometry method （ UPLC-MS/MS） was established for the residual study of cefquinome sulfate in milk. 18 healthy cows that just entering the dry period were selected and were randomly divided into 6 groups. The 6 groups of cow were respectably administrated cefquinome sulfate intramammary infusion （ dry period） once in mammary region at the dose of 3 g for each region and their milk were collected after calving. The results demonstrated that： administrated 7 days before preterm birth, concentration of cefquinome in milk collected 72h after calving decreased to about MRL;administrated 14 and 21 days before preterm birth, concentration of cefquinome in milk collected 12h after calving dropped below MRL, all below the detection limit; administrated 28、35 and 42 days before preterm birth, concentration of cefquinome in all the milk were below the detection limit. It is suggested that the milk withholding period were respectably 5, 1 and 0 days that administrated cefquinome sulfate intramammary infusion7, 14 and 21 days before preterm birth.