Can lameness prevalence in dairy herds be predicted from farmers' reports of their motivation to control lameness and barriers to doing so? An observational study from New Zealand

Understanding what motivates and prevents behavioral change in farmers is a critical step in disease control in dairy cattle. A total of 101 New Zealand dairy farmers across 8 regions were randomly enrolled into a cross-sectional study to investigate farmer barriers and motivators to lameness control for cows managed 100% at pasture, and the relationship between these responses and the true lameness status on farm. Trained technicians lameness scored all lactating cows on the enrolled farms on 2 occasions during one lactation. Farm-level prevalence proportions were calculated as the mean of the 2 lameness scores. Enrolled farmers were asked their perception of lameness in the current milking season and responded to 26 ordinal Likert-type items with 5 options ranging from not important at all to extremely important. The questions were grouped under 3 categories; barriers to lameness control (n = 9), impacts of lameness (n = 10), and motivators to control lameness (n = 7). The association between farmer perception of lameness and lameness prevalence was reported using linear regression. Multiple factor analysis was conducted to identify latent variable themes within the responses. Linear discriminant analysis was used to assess if barriers, impacts and motivators could be used to predict farmer perception of lameness, and lameness prevalence. Lameness prevalence was 0.8% greater on farms where farmers perceived lameness as a moderate or a major lameness problem compared with on farms where the farmer perceived lameness as a minor/not a problem. Farmers ranked all potential motivators to lameness control as important, and declared few barriers to be important at preventing them from controlling lameness. Feeling sorry for lame cows and pride in a healthy herd were the most important motivators, with lack of time and skilled labor the most important barriers. The most important impacts of lameness were cow-related factors such as pain and production, with farm and industry impacts of less importance. Farmers place different weightings of importance on barriers to lameness control compared with motivators for lameness control. The impacts and motivators were strongly correlated with the first dimension from the multiple factor analysis, with only weak correlation between barriers and the first dimension. Linear discriminant analysis identified that the importance that farmers place on barriers motivators and impacts of lameness were poor predictors of farmers' belief in regard to their lameness problem, or actual lameness prevalence (above or below the median lameness prevalence for the study cohort). Despite relatively low lameness prevalence, many New Zealand dairy farmers believe lameness is a problem on their farm, and they rank welfare impacts of lameness of high importance. To investigate how farmer behavior change can be used to manage lameness, future studies should consider theoretical social science frameworks beyond the theory of planned behavior, and/or involve prospective interventional studies investigating farmer actions instead of beliefs. Interpretive Summary: New Zealand dairy farmers placed greater importance on animal-level impacts of lameness compared with financial and industry impacts. Different weightings were placed on barriers to lameness control compared with motivators for lameness control, with farmers ranking all potential motivators to lameness control as important, and declaring that there were few barriers that prevented them controlling lameness. Farmer barriers and motivators were poor predictors of lameness prevalence and lameness perception, and farmer perception of lameness was poorly correlated to lameness prevalence. Prospective studies are needed to investigate how changing farmer behavior can be used to assist in lameness control.