Botaro Bruno Garcia, Cortinhas Cristina Simões, Dibbern Aline Gerato, e Silva Luis Felipe Prada, Benites Nilson Roberti, dos Santos Marcos Veiga
Department of Preventive Veterinary Medicine and Animal Health, School of Veterinary Medicine and Animal Sciences, University of São Paulo, 87 - Cidade Universitária, São Paulo, 05508-270, Brazil.
Trop Anim Health Prod. 2015 Jan;47(1):61-6. doi: 10.1007/s11250-014-0683-5. Epub 2014 Oct 16.
Staphylococcus aureus (S. aureus) is the most prevalent infectious microorganism affecting dairy cattle worldwide, and its pathogenic characteristics facilitate its spread in dairy herds. S. aureus intramammary infections (IMI) are mainly subclinical, and associated losses can exceed average herd losses where the pathogen is not isolated. However, the extent it affects milk composition at udder and quarter levels is still unknown, and cow composite milk losses may be underestimated due to the dilution effect. The aim of this study was to investigate the effects of S. aureus subclinical mastitis on mammary quarter milk yield and composition. In order to determine the effects of the pathogen on milk yield and composition at quarter level, a pairwise comparison of infected and non-infected mammary quarters (n = 28) from two dairy herds was carried out. Quarters were individually milked, and milk production and composition were assessed. S. aureus has increased somatic cell counts at quarter level; however, no effect of S. aureus IMI on milk lactose, fat, and protein contents was observed. Fat yield from infected quarters decreased, but losses due to the infection caused by S. aureus were not associated with quarter positioning in cows.
金黄色葡萄球菌是全球影响奶牛的最常见传染性微生物，其致病特性促使其在奶牛群中传播。金黄色葡萄球菌引起的乳房内感染（IMI）主要为亚临床感染，在未分离出该病原体的情况下，相关损失可能超过牛群的平均损失。然而，其在乳房和乳腺区水平上对牛奶成分的影响程度仍不明确，由于稀释效应，奶牛混合奶的损失可能被低估。本研究的目的是调查金黄色葡萄球菌亚临床乳腺炎对乳腺区产奶量和成分的影响。为了确定该病原体在乳腺区水平上对产奶量和成分的影响，对来自两个奶牛群的受感染和未受感染的乳腺区（n = 28）进行了成对比较。对每个乳腺区单独挤奶，并评估产奶量和成分。金黄色葡萄球菌在乳腺区水平上增加了体细胞计数；然而，未观察到金黄色葡萄球菌IMI对牛奶乳糖、脂肪和蛋白质含量有影响。受感染乳腺区的脂肪产量下降，但由金黄色葡萄球菌感染导致的损失与奶牛乳腺区的位置无关。
