Explaining farmers' adoption of mastitis control practices using psychological constructs from the theory of planned behavior.

• Subjective norm, farmers perceived social pressure, influence mastitis control. • Farmers' perception of being able to control the mastitis situation decides which preventive actions are used. • Understanding how to affect farmers behavior in their usage of preventive actions can have positive effects on animal health and welfare. Mastitis control options (MCOs) are management actions that are adopted to prevent mastitis in dairy herds. In this study, the psychological constructs attitude, subjective norms and perceived behavioral control are used to explain farmers' adoption of MCOs. So far, little research has used psychological constructs to explain adoption of MCOs. Based on recommendations by a Swedish dairy association (Växa) aimed at farmers, a total of 15 different management areas, representing MCOs for contagious and environmental bacteria, were used to characterize adoption behaviors. A total of 286 Swedish full-time farmers specializing in dairy production participated in the survey. Four different farmer groups were identified through a cluster analysis of similarities in how farmers adopted MCOs together with data on bulk milk somatic cell count and subjectively evaluated somatic cell counts on the farms. Regression analyses were performed to test whether the psychological constructs could explain differences in adoption across the MCO groups. Results revealed that farmers' decisions about which set of mastitis control options to adopt as preventive actions were explained by the farmers' perceived behavioral control of the situation and by differences in subjective norm. The attitude construct did not contribute to predicting the adoption of mastitis control options. Results suggest that work aimed at implementing MCOs should be complemented by programs specifically designed to improve the ability of farmers to use and/or combine MCOs to both alleviate and prevent mastitis. They also suggest that there is little to gain from programs aimed at fostering attitudes to prevent mastitis. We interpret the findings as indicating a need to strengthen perceived behavioral control as well as subjective norms among Swedish farmers' regarding their preventive work with mastitis. Understanding how to affect farmers' behavior, and thus reducing and controlling mastitis, will have positive effects on animal health and welfare in general. [ABSTRACT FROM AUTHOR]