Tiergesundheit in der ökologischen Milchviehhaltung - Status quo sowie (Weiter-) Entwicklung, Anwendung und Beurteilung eines präventiven Konzeptes zur Herdengesundheitsplanung | Animal health in organic dairy farming - Health state as well as development, application and evaluation of a preventive herd health planning concept

The prevention of animal health problems is crucial in organic livestock farming: this may be achieved by choosing appropriate animal housing conditions as well as suitable breeds and, offering high quality feedstuffs, allowing grazing or outdoor-running, and considering proper stocking densities. To date, relatively little is known about the specific dairy health situation under the conditions of organic husbandry and specific preventive concepts are hardly known to most organic milk producers. The objectives of the present thesis were, first, to assess the status quo of the animal health situation in organic dairy farming through a survey in a representative sample of farms; secondly, to develop a concept for farm-individual herd health plans; and, thirdly, to apply such health plans in the course of intervention studies on organic dairy farms. Additionally, studies of inter-observer agreement regarding locomotion scoring and a survey, which evaluated the acceptance of herd health plans by the farmers, were carried out. The thesis consists of an introduction to the topic followed by five chapters and a concluding summary. The first chapter contains results from an investigation which analysed the status quo of the animal health situation of organic dairy farming in Germany. On-farm surveys with regard to cow health, medicine use and milk recording data in 50 (year 2002/ 2003) and 43 (2004/ 2005) representative farms revealed that production diseases such as clinical mastitis, lameness and metabolic disorders seriously affect organic dairy farming. Prevalences and incidences (e.g. mastitis) were similar in range to those found in conventional dairy farming and specific concepts for prevention were hardly known. A lameness intervention study in organic dairy farming is in the focus of the second chapter. The aim of this study was to develop and validate a preventive animal health concept, taking lameness as an example, and to demonstrate that it can successfully be implemented into practice. Farm-individual catalogues of measures were developed in cooperation with the farm manager and implemented on 21 intervention farms. The lameness situation was then recorded during regular farm visits over a period of four years (2005 - 2009) and compared with the situation on 19 control farms, where no measures were in effect. Results showed that lameness prevalence was significantly and consistently reduced on the intervention farms by more than 50%. This was also the case, when the baseline situation was considered in the statistical model. The prevalence of limb injuries (here: swelling of the carpal joint) was also reduced by introducing specific measures to improve cow comfort of the lying surface. In our studies, animal related parameters were recorded using subjective assessment protocols, e.g. locomotion scoring, which can be easily applied on-farm and do not require technical equipment. These assessments are suitable for on-farm surveys provided that an acceptable level of inter-observer reliability can be assured. In the third chapter we therefore evaluated the training effect for an observer in using a five-point locomotion scoring system. The agreement between an experienced and a na