Bludau M J, Maeschli A, Leiber F, Klocke P, Berezowski J A, Bodmer M, Vidondo B
Department of Livestock Science, Research Institute of Organic Agriculture (FiBL), Ackerstrasse 113, 5070 Frick, Switzerland.
Veterinary Public Health Institute, University of Bern, Schwarzenburgstrasse 155, 3097 Liebefeld, Switzerland.
Prev Vet Med. 2016 Jul 1;129:23-34. doi: 10.1016/j.prevetmed.2016.04.013. Epub 2016 May 13.
Healthy replacement heifers are one of the foundations of a healthy dairy herd. Farm management and rearing systems in Switzerland provide a wide variety of factors that could potentially be associated with intramammary infections (IMI) in early lactating dairy heifers. In this study, IMI with minor mastitis pathogens such as coagulase-negative staphylococci (CNS), contagious pathogens, and environmental major pathogens were identified. Fifty-four dairy farms were enrolled in the study. A questionnaire was used to collect herd level data on housing, management and welfare of young stock during farm visits and interviews with the farmers. Cow-level data such as breed, age at first calving, udder condition and swelling, and calving ease were also recorded. Data was also collected about young stock that spent a period of at least 3 months on an external rearing farm or on a seasonal alpine farm. At the quarter level, teat conditions such as teat lesions, teat dysfunction, presence of a papilloma and teat length were recorded. Within 24h after parturition, samples of colostral milk from 1564 quarters (391 heifers) were collected aseptically for bacterial culture. Positive bacteriological culture results were found in 49% of quarter samples. Potential risk factors for IMI were identified at the quarter, animal and herd level using multivariable and multilevel logistic regression analysis. At the herd level tie-stalls, and at cow-level the breed category "Brown cattle" were risk factors for IMI caused by contagious major pathogens such as Staphylococcus aureus (S. aureus). At the quarter-level, teat swelling and teat lesions were highly associated with IMI caused by environmental major pathogens. At the herd level heifer rearing at external farms was associated with less IMI caused by major environmental pathogens. Keeping pregnant heifers in a separate group was negatively associated with IMI caused by CNS. The odds of IMI with coagulase-negative staphylococci increased if weaning age was less than 4 months and if concentrates were fed to calves younger than 2 weeks. This study identified herd, cow- and quarter-level risk factors that may be important for IMI prevention in the future.
健康的后备小母牛是健康奶牛群的基础之一。瑞士的农场管理和饲养系统提供了多种可能与初产奶牛早期乳房内感染（IMI）相关的因素。在本研究中，确定了由凝固酶阴性葡萄球菌（CNS）等轻度乳腺炎病原体、传染性病原体和环境主要病原体引起的IMI。54个奶牛场参与了该研究。通过问卷调查在农场访问期间收集有关幼畜饲养、管理和福利的畜群水平数据，并与农民进行访谈。还记录了奶牛水平的数据，如品种、初产年龄、乳房状况和肿胀情况以及产犊难易程度。还收集了在外部饲养场或季节性高山农场度过至少3个月的幼畜的数据。在乳区水平，记录了乳头状况，如乳头损伤、乳头功能障碍、乳头瘤的存在和乳头长度。分娩后24小时内，无菌采集了1564个乳区（391头小母牛）的初乳样本进行细菌培养。在49%的乳区样本中发现了阳性细菌培养结果。使用多变量和多水平逻辑回归分析在乳区、动物和畜群水平确定了IMI的潜在风险因素。在畜群水平，拴系牛栏，在奶牛水平，“黄牛”品种类别是由金黄色葡萄球菌（S. aureus）等传染性主要病原体引起的IMI的风险因素。在乳区水平，乳头肿胀和乳头损伤与环境主要病原体引起的IMI高度相关。在畜群水平，外部农场饲养小母牛与环境主要病原体引起的IMI较少相关。将怀孕小母牛单独分组与CNS引起的IMI呈负相关。如果断奶年龄小于4个月且在犊牛2周龄前喂食精饲料，则凝固酶阴性葡萄球菌引起的IMI几率会增加。本研究确定了未来可能对预防IMI很重要的畜群、奶牛和乳区水平的风险因素。
