PDF(Pubmed)
Abstract：
BACKGROUND: Intramammary infection is the result of invasion and multiplication of microorganisms in the mammary gland and commonly leads to mastitis in dairy animals. Although much has been done to improve cows\' udder health, mastitis remains a significant and costly health issue for dairy farmers, especially if subclinical. In this study, quarter milk samples from clinically healthy cows were harvested to detect pathogens via quantitative PCR (qPCR) and evaluate changes in individual milk traits according to the number of quarters infected and the type of microorganism(s). A commercial qPCR kit was used for detection of Mycoplasma bovis, Mycoplasma spp., Staphylococcus aureus, coagulase-negative staphylococci (CNS), Streptococcus agalactiae, Streptococcus dysgalactiae, Streptococcus uberis, Prototheca spp., Escherichia coli, Klebsiella spp., Enterococcus spp. and Lactococcus lactis ssp. lactis. Quarter and pooled milk information of 383 Holstein, 132 Simmental, 129 Rendena, and 112 Jersey cows in 9 Italian single-breed herds was available.
RESULTS: Among the cows with pathogen(s) present in at least 1 quarter, CNS was the most commonly detected DNA, followed by Streptococcus uberis, Mycoplasma bovis, and Streptococcus agalactiae. Cows negative to qPCR were 206 and had the lowest milk somatic cell count. Viceversa, cows with DNA isolated in ≥ 3 quarters were those with the highest somatic cell count. Moreover, when major pathogens were isolated in ≥ 3 quarters, milk had the lowest casein index and lactose content. In animals with pathogen(s) DNA isolated, the extent with whom milk yield and major solids were impaired did not significantly differ between major and minor pathogens.
CONCLUSIONS: The effect of the number of affected quarters on the pool milk quality traits was investigated in clinically healthy cows using a commercial kit. Results remark the important negative effect of subclinical udder inflammations on milk yield and quality, but more efforts should be made to investigate the presence of untargeted microorganisms, as they may be potentially dangerous for cows. For a smarter use of antimicrobials, analysis of milk via qPCR is advisable - especially in cows at dry off - to identify quarters at high risk of inflammation and thus apply a targeted/tailored treatment.
RESULTS: Among the cows with pathogen(s) present in at least 1 quarter, CNS was the most commonly detected DNA, followed by Streptococcus uberis, Mycoplasma bovis, and Streptococcus agalactiae. Cows negative to qPCR were 206 and had the lowest milk somatic cell count. Viceversa, cows with DNA isolated in ≥ 3 quarters were those with the highest somatic cell count. Moreover, when major pathogens were isolated in ≥ 3 quarters, milk had the lowest casein index and lactose content. In animals with pathogen(s) DNA isolated, the extent with whom milk yield and major solids were impaired did not significantly differ between major and minor pathogens.
CONCLUSIONS: The effect of the number of affected quarters on the pool milk quality traits was investigated in clinically healthy cows using a commercial kit. Results remark the important negative effect of subclinical udder inflammations on milk yield and quality, but more efforts should be made to investigate the presence of untargeted microorganisms, as they may be potentially dangerous for cows. For a smarter use of antimicrobials, analysis of milk via qPCR is advisable - especially in cows at dry off - to identify quarters at high risk of inflammation and thus apply a targeted/tailored treatment.
摘要：
背景：乳腺内感染是微生物在乳腺中入侵和繁殖的结果，通常会导致乳品动物的乳腺炎。尽管在改善奶牛乳房健康方面已经做了很多工作，乳腺炎仍然是奶农的一个重要和昂贵的健康问题，尤其是亚临床的.在这项研究中,收获来自临床健康奶牛的四分之一乳样品以通过定量PCR(qPCR)检测病原体,并根据感染的四分之一的数量和微生物的类型评估个体乳性状的变化。商业qPCR试剂盒用于检测牛支原体，支原体属。,金黄色葡萄球菌,凝固酶阴性葡萄球菌（CNS），无乳链球菌，乳酸链球菌，赤子链球菌,原藻属。,大肠杆菌,克雷伯菌属。,肠球菌属。和乳酸乳球菌ssp。乳酸。383个荷斯坦州的季度和汇总牛奶信息，132西门塔尔，129Rendena,在9个意大利单一品种的牧群中，有112头泽西奶牛。
结果：在至少1个季度出现病原体的奶牛中，中枢神经系统是最常见的检测DNA，其次是赤霉病链球菌,牛支原体,和无乳链球菌.qPCR阴性的奶牛为206,并且具有最低的乳体细胞计数。反之亦然,DNA分离≥四分之三的奶牛是体细胞计数最高的奶牛。此外，当主要病原体在≥3个季度被分离时，牛奶的酪蛋白指数和乳糖含量最低。在分离了病原体DNA的动物中，主要病原体和次要病原体的产奶量和主要固体受损程度没有显着差异。
结论：使用商业试剂盒在临床健康奶牛中研究了受影响的季度数量对池乳质量性状的影响。结果表明，亚临床乳房炎症对牛奶产量和质量的重要负面影响，但是应该做出更多的努力来调查非目标微生物的存在，因为它们可能对奶牛有潜在危险。为了更聪明地使用抗菌药物，建议通过qPCR分析牛奶-特别是在干牛中-以确定炎症高风险的季度，从而应用靶向/定制治疗。
结果：在至少1个季度出现病原体的奶牛中，中枢神经系统是最常见的检测DNA，其次是赤霉病链球菌,牛支原体,和无乳链球菌.qPCR阴性的奶牛为206,并且具有最低的乳体细胞计数。反之亦然,DNA分离≥四分之三的奶牛是体细胞计数最高的奶牛。此外，当主要病原体在≥3个季度被分离时，牛奶的酪蛋白指数和乳糖含量最低。在分离了病原体DNA的动物中，主要病原体和次要病原体的产奶量和主要固体受损程度没有显着差异。
结论：使用商业试剂盒在临床健康奶牛中研究了受影响的季度数量对池乳质量性状的影响。结果表明，亚临床乳房炎症对牛奶产量和质量的重要负面影响，但是应该做出更多的努力来调查非目标微生物的存在，因为它们可能对奶牛有潜在危险。为了更聪明地使用抗菌药物，建议通过qPCR分析牛奶-特别是在干牛中-以确定炎症高风险的季度，从而应用靶向/定制治疗。
