Using Thermal Imaging to Detect Tail Tip Alterations in Dairy Cows

In fattening bulls tail tip alterations are described as health issues associated with (sub)acute rumen acidosis and lameness. Investigations of dairy cows’ tail tips are scarce; however, there is evidence that tail tip alterations occur as a result of intensive feeding management and metabolic imbalance. In June 2020, we investigated 68 German Holstein cows for tail tip alterations using a handheld thermal camera (FLIR® T1030). Thermal images of the shaved tail tip were taken from two different perspectives: (p1) tail in front of the udder and (p2) held tail in front of the ground. Additionally, all cows were evaluated for any kind of tail tip alterations, body condition score (BCS), and locomotion score (LMS). Milk yield data, resulting from latest performance testing were collected, too. Images were analysed using FLIR Tool+ and a generalised linear model was used to correct measured temperatures for fixed effects. The prevalence of tail tip alterations, regardless the findings, was 94%. Raw temperature data showed high correlations of r² = 0.79 for maximum and average temperature and r² = 0.70 for minimum temperature between p1 and p2 (P < 0.001). Tail tip necroses and BCS > 3 decreased the tail’s temperature, while swelling of the tail tip increased its temperature. Average, maximum and minimum temperatures for perspective 1 and 2 were 34.05 (±0.16) and 33.78 (±0.20) °C, 35.46 (±0.11) and 35.52 (±0.11) °C, and 30.30 (±0.30) and 29.22 (±0.38) °C, respectively. Temperatures of necrotic tissues (n = 4) decreased on average by 8.38 °C compared to the average temperature and were close to the minimum. We concluded thermal imaging can be used for the detection of alterations regarding the tail’s temperature, which could allow an early-warning system for swellings, probably caused by inflammation and possibly resulting in necroses. Further studies are needed to evaluate the praevalence of tail tip alterations in dairy cows on larger samples and to clarify their etiology. However, thermal imaging can be used as an early-warning system for tail alterations. Each early-warning system regarding health issues, improves animal welfare as it allows adapting management strategies early.