Michael Charalambia K, Lianou Daphne T, Vasileiou Natalia G C, Mavrogianni Vasia S, Petinaki Efthymia, Fthenakis George C
Veterinary Faculty, University of Thessaly, 43100 Karditsa, Greece.
Faculty of Animal Science, University of Thessaly, 41110 Larissa, Greece.
Animals (Basel). 2023 Oct 22;13(20):3295. doi: 10.3390/ani13203295.
The objectives of this work were (a) to describe the incidence risk of subclinical mastitis in dairy flocks throughout the milking period, (b) to present potential associations of subclinical mastitis with the quality of milk and (c) to identify risk factors for high-incidence risk of the infection. A longitudinal study was performed in 12 dairy sheep flocks in Greece. Mammary secretion samples from 240 ewes and bulk-tank milk samples were collected in four repeated visits over a period of six months for bacteriological, chemical and cytological examinations. Overall, the incidence risk of subclinical mastitis throughout the study period was 51.7%, and it varied among farms from 25.0% to 75.0%. The respective figure for staphylococcal subclinical mastitis was 48.8%. The incidence risk of recurrence of subclinical mastitis among ewes in the flocks was 35.4%. The most frequently identified bacteria from cases of subclinical mastitis were and ; of the mastitis-causing staphylococcal isolates, 65.4% were biofilm-forming. Somatic cell counts in bulk-tank milk progressively increased as the lactation period advanced, with significant increases seen on the third and fourth visits to the farms. Somatic cell counts in bulk-tank milk correlated well with prevalence of subclinical mastitis in flocks. A significant inverse correlation and a significant positive correlation were seen for prevalence of subclinical mastitis versus total protein content or added water in bulk-tank milk. During multivariable analysis, younger age of newborns when taken away from the dam and consequently delayed start of milking of ewes, omission of anti-mastitis vaccination of ewes and lack of employed staff on the farms emerged to be significantly associated (positively) with increased incidence risk of subclinical mastitis.
(a) 描述整个挤奶期奶牛群亚临床型乳腺炎的发病风险；(b) 阐述亚临床型乳腺炎与牛奶质量之间的潜在关联；(c) 确定该感染高发病风险的危险因素。在希腊的12个奶羊群中开展了一项纵向研究。在六个月的时间里，分四次重复采集了240只母羊的乳腺分泌物样本和储奶罐牛奶样本，用于细菌学、化学和细胞学检查。总体而言，在整个研究期间，亚临床型乳腺炎的发病风险为51.7%，各农场之间的风险有所不同，在25.0%至75.0%之间。葡萄球菌性亚临床型乳腺炎的相应比例为48.8%。羊群中母羊亚临床型乳腺炎复发的发病风险为35.4%。从亚临床型乳腺炎病例中最常鉴定出的细菌是 和 ；在引起乳腺炎的葡萄球菌分离株中，65.4%能够形成生物膜。随着泌乳期推进，储奶罐牛奶中的体细胞计数逐渐增加，在第三次和第四次农场访视时出现显著增加。储奶罐牛奶中的体细胞计数与羊群中亚临床型乳腺炎的患病率密切相关。亚临床型乳腺炎的患病率与储奶罐牛奶中的总蛋白含量或加水情况呈显著负相关和显著正相关。在多变量分析中，新生羔羊断奶时间较早从而导致母羊挤奶开始时间延迟、母羊未进行预防乳腺炎的疫苗接种以及农场缺乏雇佣员工，这些因素均与亚临床型乳腺炎发病风险增加显著正相关。
