Nickerson S C
Louisiana Agricultural Experiment Station, Louisiana State University Agricultural Center, Homer 71040.
J Am Vet Med Assoc. 1987 Dec 1;191(11):1484-8.
Investigations on bovine teat-end defenses and their role in mastitis control were reviewed. Alteration of teat canal keratin by method of intramammary drug infusion through the teat canal influenced the number of new infections. At the beginning of the nonlactating period, 2 methods of administering antibiotic were studied: full insertion of treatment syringe cannulas into teat cisterns and expelling contents and partial insertion of cannulas into the distal 2 to 3 mm of teat canals and slowly infusing contents. Partial cannula insertion reduced new infections by 50% and is an easily adopted management tool to reduce prevalence of mastitis. Intramammary devices used during lactation and the nonlactating period increased leukocyte concentrations in mammary secretions. An abraded polyethylene coil device reduced clinical mastitis and increased milk yield. Staphylococci colonize teat canal keratin and lacteal secretions of dairy heifers as early as 9 months of age, leading to intramammary infection at time of calving and persisting into lactation. Subsequent somatic cell counts are associated with milk production losses. Previously, such infections were shown to be associated only with older, mature animals.
本文综述了关于奶牛乳头末端防御机制及其在乳腺炎控制中作用的研究。通过乳头管进行乳房内药物灌注的方法改变乳头管角质，会影响新感染的数量。在非泌乳期开始时，研究了两种抗生素给药方法：将治疗注射器套管完全插入乳头池并排出内容物，以及将套管部分插入乳头管远端2至3毫米处并缓慢注入内容物。部分套管插入可使新感染减少50%，是一种易于采用的管理工具，可降低乳腺炎的发病率。在泌乳期和非泌乳期使用的乳房内装置会增加乳腺分泌物中的白细胞浓度。一种磨损的聚乙烯线圈装置可减少临床乳腺炎并提高产奶量。葡萄球菌早在9月龄时就定植于奶牛乳头管角质和乳腺分泌物中，导致产犊时乳房内感染，并持续到泌乳期。随后的体细胞计数与产奶量损失相关。以前，此类感染仅被认为与年龄较大的成熟动物有关。
