Trinidad P, Nickerson S C, Alley T K
Mastitis Research Laboratory, Louisiana State University Agricultural Center, Homer 71040.
J Dairy Sci. 1990 Jan;73(1):107-14. doi: 10.3168/jds.S0022-0302(90)78652-3.
Teat canal keratin (n = 461) and mammary gland secretions (n = 370) were collected from 31 unbred and 85 primigravid Jersey heifers from one research and three commercial dairy herds. Of 97 heifers from which secretion samples were obtained, 96.9% had intramammary infections and 29% showed clinical symptoms. Seventy-five percent of quarters were infected. Staphylococcus aureus were isolated from 36 (37.1%) heifers and 55 (14.9%) quarters. One hundred and eight (93.1%) heifers and 326 (70.7%) quarters had teat canals colonized with mastitis pathogens. Staphylococcus aureus were isolated from teat canal keratin samples from 36 (31%) heifers and 57 (12.3%) quarters. The three most common species isolated from secretion and teat canal keratin samples were Staphylococcus chromogenes, Staphylococcus hyicus, and S. aureus. Secretions from infected (n = 240) and uninfected (n = 85) quarters had SCC of 13.6 X 10(6)/ml and 5.7 X 10(6)/ml. Macrophages were the most numerous cell type in secretions of infected and uninfected quarters. Quarters with teat canal colonization, but with no intramammary infections, exhibited higher SCC in secretion (9.3 X 10(6)/ml) than quarters without both teat canal colonizations and intramammary infections (4.9 X 10(6)/ml). Data indicated that intramammary infections and teat canal colonizations were more prevalent and SCC higher than previously realized in dairy heifers.
从一个研究型和三个商业奶牛场的31头未孕和85头初产泽西小母牛中采集了乳头管角质（n = 461）和乳腺分泌物（n = 370）。在获得分泌物样本的97头小母牛中，96.9%患有乳房内感染，29%出现临床症状。75%的乳腺区受到感染。从36头（37.1%）小母牛和55个（14.9%）乳腺区分离出金黄色葡萄球菌。108头（93.1%）小母牛和326个（70.7%）乳腺区的乳头管被乳腺炎病原体定植。从36头（31%）小母牛和57个（12.3%）乳腺区的乳头管角质样本中分离出金黄色葡萄球菌。从分泌物和乳头管角质样本中分离出的三种最常见的菌种是产色葡萄球菌、猪葡萄球菌和金黄色葡萄球菌。感染乳腺区（n = 240）和未感染乳腺区（n = 8）分泌物的体细胞计数分别为13.6×10⁶/ml和5.7×10⁶/ml。巨噬细胞是感染和未感染乳腺区分泌物中数量最多的细胞类型。乳头管定植但无乳房内感染的乳腺区，其分泌物中的体细胞计数（9.3×10⁶/ml）高于既无乳头管定植也无乳房内感染的乳腺区（4.9×10⁶/ml）。数据表明，乳房内感染和乳头管定植在奶牛小母牛中比之前认识到的更为普遍，体细胞计数也更高。
