The scoring of the body condition at specific time points during the lactation cycle has proven to be essential in the nutritional management of modern dairy herds. The 'Thunder Measure (TM) Vet Device' has recently been developed by Ingenera SA, Switzerland to accurately and objectively measure the body condition score (BCS) of dairy cows in the field. Based on a smartphone app linked to a laser device, the system makes an analysis of three dorsal view photographs taken, for example, when cows are lined up in the feed alley. In the present study, the correlation and repeatability of the system were examined in comparison with the conventional visual measurement of BCS and ultrasonographic measurement of the backfat thickness (BFT). The conventional measurement of the BCS was done by a veterinary surgeon experienced in body condition scoring and by less experienced veterinary undergraduate students. The results obtained via the TM Vet Device were only moderately correlated with the BFT measurements (r=0.38, P<0.001), but were highly correlated (r=0.82, P<0.001) and showed good agreement with the BCS results obtained by the experienced veterinary surgeon. The BCS results obtained by the undergraduate students were highly variable, leading to a highly variable correlation with the results gathered using the TM Vet Device (r=0.23 (P<0.05) to r=0.74 (P<0.001)). The repeatability of the results obtained by the device was very high (91%). Only the repeatability of the results obtained by the experienced veterinarian (93%) and the BFT measurement (96%) were higher. In lean animals, some overscoring by the device was noted in comparison with the scores given by the experienced veterinary surgeon, although this overscoring diminished as the body condition score assigned by the veterinary surgeon increased.
The ease to use and the accuracy of the results obtained allow the TM Vet Device to be considered a useful tool in the nutritional management of a modern dairy herd