Department of Dairy Science, University of Wisconsin, Madison 53706; Departamento de Ciência dos Alimentos, Universidade Federal de Lavras, Minas Gerais, Brazil 37200-000.
Departamento de Ciência dos Alimentos, Universidade Federal de Lavras, Minas Gerais, Brazil 37200-000.
J Dairy Sci. 2017 Sep;100(9):7522-7533. doi: 10.3168/jds.2017-12547. Epub 2017 Jun 21.
Mammary gland quarters have usually been considered to be anatomically and physiologically independent, but some recent research has indicated more interdependence than previously reported. The objective of this study was to compare milk composition (fat, total protein, lactose, solids-not-fat, and chloride) and health status (somatic cell count, differential leukocyte count, and lactate dehydrogenase) of milk samples from unaffected mammary glands of an udder with a single clinically inflamed quarter to results of milk samples from healthy mammary glands of healthy cows. The study was designed as a prospective case control study with case and control cows matched by parity and days in milk. Cases were defined as cows (n = 59) experiencing clinical mastitis in a single mammary gland, and controls (n = 59) were defined as cows that had not experienced clinical mastitis during the current lactation. Quarter milk samples were collected from all mammary glands adjacent to clinically affected quarters of cases and from the same mammary glands of controls. Samples were used to assess concentration of chloride and lactate dehydrogenase, fat, total protein, solids-not-fat, somatic cell count, and differential leukocyte count. Microbiological analysis was also performed on milk samples obtained from clinically affected mammary glands (n = 59). Logistic regression models were used to assess possible associations among quarter somatic cell count (≥150,000 cells/mL) and quarter type (adjacent to case or control). Multivariate linear models were used to compare milk composition and health status between quarter types. A total of 170 quarters were enrolled per group. Milk obtained from adjacent quarters of cases contained a lesser concentration of total protein, lactose, and solids-not-fat, but had a greater concentration of fat and chloride. The somatic cell count, total leukocyte count, and absolute numbers of neutrophils, lymphocytes, and macrophages were all increased in milk obtained from adjacent quarters of case cows compared with milk obtained from quarters of control cows. The relative proportion of neutrophils was increased, whereas the proportion of macrophages was decreased in milk obtained from cases. Approximately 30% of milk samples obtained from adjacent quarters of cases had a somatic cell count ≥150,000 cells/mL compared with 12% of milk samples obtained from quarters of control cows. The position of the mammary gland was not associated with any outcomes. In conclusion, our results support previous research that indicates the immune response to intramammary infection in a single mammary gland quarter alters milk composition and health status throughout the udder.
乳腺象限通常被认为在解剖学和生理学上是独立的，但最近的一些研究表明，它们之间的相互依存关系比以前报道的更为密切。本研究的目的是比较单侧临床乳腺炎奶牛未受影响的乳腺与健康奶牛健康乳腺的乳汁成分（脂肪、总蛋白、乳糖、非脂固形物和氯）和健康状况（体细胞计数、白细胞分类计数和乳酸脱氢酶）。该研究设计为病例对照前瞻性研究，病例和对照奶牛按胎次和泌乳天数匹配。病例定义为单侧乳腺发生临床乳腺炎的奶牛（n=59），对照定义为当前泌乳期内未发生临床乳腺炎的奶牛（n=59）。从病例的临床感染乳腺相邻的所有乳腺象限和对照的相同乳腺象限采集乳样。使用这些样本评估氯和乳酸脱氢酶、脂肪、总蛋白、非脂固形物、体细胞计数和白细胞分类计数的浓度。还对来自临床感染乳腺的奶样进行了微生物分析（n=59）。使用逻辑回归模型评估象限体细胞计数（≥150,000 个细胞/ml）与象限类型（与病例或对照相邻）之间的可能关联。使用多元线性模型比较象限类型之间的乳汁成分和健康状况。每组纳入 170 个象限。病例相邻象限采集的奶样总蛋白、乳糖和非脂固形物浓度较低，但脂肪和氯浓度较高。与对照牛奶相比，来自病例牛相邻象限的奶样中的体细胞计数、总白细胞计数以及中性粒细胞、淋巴细胞和巨噬细胞的绝对数量均增加。来自病例的奶样中中性粒细胞的相对比例增加，而巨噬细胞的比例减少。与对照牛奶相比，来自病例相邻象限的约 30%的奶样体细胞计数≥150,000 个细胞/ml，而来自对照牛奶的奶样中仅 12%的奶样体细胞计数≥150,000 个细胞/ml。乳腺位置与任何结果均无关。总之，我们的结果支持了以前的研究，表明单个乳腺象限的乳腺炎的免疫反应会改变整个乳房的乳汁成分和健康状况。
