Management practices’ effect on milk production, somatic cell count and mastitis in Swedish organic dairy farms

Summary

The most common animal health problem in organic dairy production is mastitis. It is considered to be one of the most serious welfare problem in dairy production, as well as an economic problem as it often leads to a reduced milk yield and reduced profit. To combat this problem, the focus in organic dairy production is laid on management strategies to e.g. reduce the use of antibiotics and improve the animal health and welfare. In 2015, the EU-funded project OrganicDairyHealth started in seven European countries, including Sweden. Within the project, an extensive survey on housing, management, health and production was sent out to organic dairy farmers in each country, and this thesis is based on the data from the Swedish survey. This master thesis’ aim was to (1) describe Swedish organic dairy farms, and to (2) assess relationships between milk production, somatic cell count (SCC), mastitis incidence, farm characteristics and management practices in Swedish organic dairy production. The Swedish survey was sent out in January 2016 and the answers included information about the production year 2014. The analysed data set included answers from 58 organic farms, corresponding to 10.6% of all organic dairy farms in Sweden 2014, and the number of answers varied between questions in the extensive questionnaire. Based on the data from the survey, the average Swedish organic dairy farm had insulated stalls and loose housing with milking robot. The farms had an average herd size of 77 cows and produced on average 8791 kg energy-corrected milk per cow and year. The most common diseases were mastitis, milk fever, and claw diseases, with mastitis being the most widespread. Most farms used three or more hygiene routines at milking, with wet cleaning of the udder and using new cleaning material for each cow being the two most commonly used routines. The majority of farmers used antibiotics and/or drying off individual udder quarters to treat clinical mastitis. Furthermore, one fourth of the farmers used homeopathic treatment to treat clinical mastitis, although no farmers used homeopathy as the only treatment. Farms with milking robot had higher milk production and higher SCC, while farms with milk line had higher mastitis incidence. Herd size was the only factor that was associated with all examined outcome variables (milk production, SCC, and mastitis). Farms with large herds had high milk production, high SCC, and low mastitis incidence. To conclude, there were farm characteristics and management practices that were of importance for milk production, SCC, and mastitis incidence in Swedish organic dairy farms. Mastitis was the most common and widespread disease and the results from this study indicates that the mastitis incidence is associated withmany farm characteristics and management practices. The variation in farm characteristics and management practices observed in this study, together with the indications of effects of these on milk production, SCC, and mastitis incidence, shows that there is not one typical Swedish organic dairy farm type, but a variety of farm types. Additionally, these results show that there is a need for development of farm specific management strategies that takes e.g. the specific housing, milking system, and health status of the farm into account.