Mišeikienė R, Tušas S, Rudejevienė J, Virgailis M, Pilarczyk B, Tomza-Marciniak A
Institute of Animal Rearing Technologies, Veterinary Academy, Lithuanian University of Health Sciences, Tilžės 18, LT-47181 Kaunas, Lithuania.
Dr. L.Kriauceliunas Small Animal Clinic, Veterinary Academy, Lithuanian University of Health Sciences, Tilžės 18, Kaunas, Lithuania.
Pol J Vet Sci. 2025 Jun;28(2):251-258. doi: 10.24425/pjvs.2025.154944.
The aim of this study was to assess the effect of lactation number, lactation stage and somatic cell count (SCC) on the presence of pathogenic or opportunistic pathogens in cow milk. A total of 1712 milk samples were collected from the udder quarters of 428 lactating Holstein breed cows for bacteriological examination. Somatic cell count was taken from the controlled bovine records. The cows were divided into four groups according to the lactation number (viz. lactation numbers 1, 2, 3, 4 and above) and into three groups according to the lactation month (viz. 1-4, 5-8, 9 months and above). The statistical analysis was performed by SPSS 27.0 software (SPSS Inc., Chicago, Illinois, USA). Frequencies of microorganisms were calculated by determining their confidence intervals (Wilson Confidence Interval 95%, CI). Various farm pathogens were identified: CNS (Coagulase negative staphylococci), S. aureus, Enterococcus spp., Str. agalactiae, E. coli. It was found that CNS and S. agalactiae increased with somatic cell count, lactation number and lactation stage. E. coli increased at the end of the lactation stage (p≤0.05). Enterococcus spp. count in milk differed significantly between cows in lactations 1 and 4 and older (p≤0.05). Pathogen number also increased with milk fat, but decreased with increased protein content (p≤0.01).
本研究的目的是评估泌乳次数、泌乳阶段和体细胞计数（SCC）对牛奶中致病性或机会性病原菌存在情况的影响。从428头泌乳荷斯坦奶牛的乳房象限采集了总共1712份牛奶样本进行细菌学检查。体细胞计数取自受控的奶牛记录。奶牛根据泌乳次数分为四组（即泌乳次数1、2、3、4及以上），并根据泌乳月份分为三组（即1 - 4个月、5 - 8个月、9个月及以上）。统计分析使用SPSS 27.0软件（SPSS公司，美国伊利诺伊州芝加哥）进行。通过确定微生物的置信区间（威尔逊95%置信区间，CI）来计算微生物的频率。鉴定出了各种农场病原菌：凝固酶阴性葡萄球菌（CNS）、金黄色葡萄球菌、肠球菌属、无乳链球菌（Str. agalactiae）、大肠杆菌。发现CNS和无乳链球菌随着体细胞计数、泌乳次数和泌乳阶段的增加而增加。大肠杆菌在泌乳阶段末期增加（p≤0.05）。泌乳1次和4次及以上的奶牛牛奶中的肠球菌属计数差异显著（p≤0.05）。病原菌数量也随着乳脂增加而增加，但随着蛋白质含量增加而减少（p≤0.01）。
