Parasite control in organic cattle farming: Management and farmers' perspectives from six European countries.

Organic ruminant production is expanding in the EU, but parasite management remains a constant challenge. Mandatory outdoor access for all age groups can increase exposure to pasture borne parasites, whilst restrictions in the prophylactic use of anthelmintics can limit parasite control. The scientific community has been working to deliver effective parasite control strategies and alternative approaches in order to slow down the development of anthelmintic resistance (AR). However, the current parasite control practices and overall awareness with regards to AR and alternative approaches on farms are largely unknown and may be causing a knowledge gap between the scientific and farming communities. Therefore, a structured survey was conducted in six European countries (Switzerland, Germany, Denmark, Netherlands, Lithuania, Sweden) to provide basic data on practices, management and farmers' perspectives for grazing and parasite control (gastrointestinal worms and liver flukes) on organic cattle farms. Overall, 375 surveys were collected (282 dairy and 93 beef farms) in 2015-2016, and analysed descriptively. Additionally, surveys from the 228 dairy farms were assessed using a double-hurdle adoption model to identify the factors involved in the decision to drench against gastrointestinal parasites. Generally, there are prominent differences between countries, with monitoring methods differing especially, which has important implications in terms of knowledge transfer. For example, media warning was the most common method in DE, while antibody testing in bulk tank milk was the common method in NL. In other countries, clinical signs (diarrhoea, hair coat quality, and reduced weight or yield) and liver condemnation data were used frequently. In general, organic farmers from the six participating countries indicated that they would accept alternative approaches despite greater cost and labour. The likelihood of drenching were higher on farms with smaller farm areas, higher number of young stock and total livestock units and farms where faecal egg counts were used to monitor the parasites. In conclusion, it was evident that grazing and parasite management varied between the countries even though they operate under the same basic principles. Parasite management strategies must therefore be country specific and disseminated with appropriate methods.