Lerondelle C, Poutrel B
Ann Rech Vet. 1984;15(1):105-12.
This study, carried out on 1217 milk goats (2428 milk samples), sampled at two different periods of lactation, showed that non-clinical mammary infections of the goat were due to major pathogens (7.5%) and coagulase-negative staphylococci (24.1%). Among major pathogens, Staphylococcus aureus was the most frequently isolated species (75.2%). However, great variations were observed between herds, in levels of infection by major pathogens. The intensity of the inflammatory response, measured by the cell count, depended on the pathogen present in the mammary gland. Evidence was found that 75% of infections persisted throughout the lactation and 61% during the dry-period. The arithmetic mean cell counts for milk samples from halves infected with major pathogens was 6.77 X 10(6) cells/ml, determined by Coulter Counter. It was 1.78 and 1.54 X 10(6) cells/ml respectively for halves infected with coagulase-negative staphylococci and non-infected halves. The arithmetic mean cell counts were higher at drying-off than in lactation. The threshold of 1 X 10(6) cells/ml was reliable for diagnosis in mid-lactation and permitted to diagnose 72% of major pathogen infections.
本研究对1217只奶山羊（2428份奶样）进行了调查，这些奶样在泌乳期的两个不同阶段采集。结果显示，奶山羊的非临床型乳腺感染是由主要病原菌（7.5%）和凝固酶阴性葡萄球菌（24.1%）引起的。在主要病原菌中，金黄色葡萄球菌是最常分离出的菌种（75.2%）。然而，不同畜群之间主要病原菌的感染水平存在很大差异。通过细胞计数测量的炎症反应强度取决于乳腺中存在的病原体。有证据表明，75%的感染在整个泌乳期持续存在，61%在干奶期持续存在。通过库尔特计数器测定，感染主要病原菌的奶样一半的算术平均细胞计数为6.77×10⁶个细胞/毫升。感染凝固酶阴性葡萄球菌的奶样一半和未感染的奶样一半的算术平均细胞计数分别为1.78×10⁶个细胞/毫升和1.54×10⁶个细胞/毫升。干奶期的算术平均细胞计数高于泌乳期。1×10⁶个细胞/毫升的阈值在泌乳中期诊断中是可靠的，能够诊断72%的主要病原菌感染。
