Laevens H, Deluyker H, Schukken Y H, De Meulemeester L, Vandermeersch R, De Muêlenaere E, De Kruif A
Faculty of Veterinary Medicine, Department of Reproduction, Obstetrics and Herd Health, University of Ghent, Belgium.
J Dairy Sci. 1997 Dec;80(12):3219-26. doi: 10.3168/jds.S0022-0302(97)76295-7.
This study examines the influence of parity, stage of lactation, and single isolations (i.e., the isolation of a microorganism that could not be reisolated in the same quarter in the next sampling) of staphylococci other than Staphylococcus aureus (coagulase-negative staphylococci), Corynebacterium bovis, or esculin-positive cocci other than Streptococcus uberis (referred to as esculin-positive cocci throughout) on the monthly log(e)-transformed somatic cell count (SCC) for 180 first, second, and third parity cows that were observed over a whole lactation. Repeated measures ANOVA was used to analyze the data. No significant effect was found for the infection variable. However, the results indicated that even single isolations of coagulase-negative staphylocci, C. bovis, or esculin-positive cocci resulted in a numerical or statistically significant increase in SCC. Least squares mean SCC (log(e)-transformed) for bacterio-logically negative cows and cows with single isolations of coagulase-negative staphylococci, C. bovis, or esculin-positive cocci were 3.90, 3.97, 4.08, and 4.17, respectively. Significant effects of parity, stage of lactation, and the interaction of parity and stage of lactation could not be found when only bacteriologically negative cows were considered. Least squares mean SCC for first, second, and third parity cows were 3.80, 3.93, and 3.97, respectively. However, the effects of parity, stage of lactation, and the interaction of parity and stage of lactation were significant when all 180 cows were included. Therefore, these effects must be due to factors that were present in the infected groups.
本研究考察了胎次、泌乳阶段以及除金黄色葡萄球菌（凝固酶阴性葡萄球菌）、牛棒状杆菌或乳房链球菌以外的其他产色苷阳性球菌（以下简称产色苷阳性球菌）的单次分离（即一种微生物在下次采样时无法在同一季度再次分离出来）对180头经整个泌乳期观察的头胎、二胎和三胎奶牛每月对数转换体细胞计数（SCC）的影响。采用重复测量方差分析对数据进行分析。未发现感染变量有显著影响。然而，结果表明，即使是凝固酶阴性葡萄球菌、牛棒状杆菌或产色苷阳性球菌的单次分离也会导致SCC在数值上或统计学上显著增加。细菌学阴性奶牛以及凝固酶阴性葡萄球菌、牛棒状杆菌或产色苷阳性球菌单次分离奶牛的最小二乘均值SCC（对数转换）分别为3.90、3.97、4.08和4.17。仅考虑细菌学阴性奶牛时，未发现胎次、泌乳阶段以及胎次和泌乳阶段交互作用的显著影响。头胎、二胎和三胎奶牛的最小二乘均值SCC分别为3.80、3.93和3.97。然而，当纳入所有180头奶牛时，胎次、泌乳阶段以及胎次和泌乳阶段交互作用的影响是显著的。因此，这些影响必定归因于感染组中存在的因素。
