Cummins K A, McCaskey T A
Department of Animal and Dairy Sciences, Auburn University 36849.
J Dairy Sci. 1987 Dec;70(12):2658-65. doi: 10.3168/jds.S0022-0302(87)80336-3.
Efficacy of multiple and single intramammary infusions of benzathine cloxacillin (500 mg/quarter) were compared for treatment of mastitis during the dry period. Treatments were three infusions, one each at 0, 7, and 14 d into the dry period; one infusion at drying off; and no infusions. Cows were grouped (30/treatment) based on previous mastitis history, mean monthly SCC, mature equivalent milk production, and pathogen detected pretreatment. Infected quarters/cow at parturition, posttreatment were 1.26, 1.6, and 2.35 for multiple, single, and no infusion groups, respectively. Milk production and somatic cell count posttreatment were not affected by treatment. Across all genera of microorganism, 75.5, 73.6, and 52.8% of infections were eliminated in the multiple, single, and no infusion groups, respectively. Primary effect of multiple infusions with cloxacillin in the dry period was to prevent new streptococcal infections. Sensitivity tests on staphylococcal isolates indicated that cloxacillin was still an effective dry cow treatment after 7 yr of use in the herd. Resistance to cloxacillin in approximately half the posttreatment staphylococcal isolates appeared to be nonenzyme (penicillinase) dependent. Multiple dry cow treatments with cloxacillin do not offer any advantage over a single treatment.
比较了苄星氯唑西林（500毫克/每个乳房象限）多次和单次乳房内灌注治疗干奶期乳腺炎的效果。治疗方法为：在干奶期第0、7和14天各灌注一次；干奶时灌注一次；不进行灌注。根据既往乳腺炎病史、每月平均体细胞数、成熟当量产奶量和治疗前检测到的病原体对奶牛进行分组（每组30头）。多次灌注组、单次灌注组和未灌注组在分娩时每头奶牛受感染的乳房象限数分别为1.26、1.6和2.35。治疗后产奶量和体细胞数不受治疗影响。在所有微生物属中，多次灌注组、单次灌注组和未灌注组分别有75.5%、73.6%和52.8%的感染被消除。干奶期多次灌注氯唑西林的主要作用是预防新的链球菌感染。对葡萄球菌分离株的敏感性测试表明，在该牛群中使用氯唑西林7年后，它仍是一种有效的干奶牛治疗药物。大约一半的治疗后葡萄球菌分离株对氯唑西林的耐药性似乎是非酶（青霉素酶）依赖性的。氯唑西林多次干奶牛治疗并不比单次治疗有任何优势。
