Comparison of manual and automated body condition scoring of commercial dairy cattle.

BACKGROUND: Body condition scoring of dairy cows estimates their body reserves. Automation allows increased data availability and reduced labour costs. The aim of this study was to compare an automated (AUT) body condition score (BCS) system to manual observers on a single commercial dairy farm in south-west England. METHODS: Three practising veterinary surgeons performed body condition scoring of 315 dairy cows using the agriculture and horticulture development board (AHDB) Body Condition Scorecard. AUT BCSs were obtained from two 3D cameras and compared to the BCSs recorded by the three operators. RESULTS: The AUT system only agreed with manual scorers at a BCS of 3. The system failed to detect cows classified as underconditioned (BCS ≤ 2.25) by any of the operators (sensitivity 0%). It also systematically underestimated the BCS of cows classified as overconditioned (BCS ≥ 3.5) by the operators. For overconditioned cows, the sensitivity of the AUT system ranged from 30.7% to 48.8% when compared with the manual operators. The AUT system also had weaker agreement with operators for Jersey cows, with Cohen's weighted kappa values of 0.28 for Jersey animals and 0.40 for Holsteins. LIMITATIONS: This study used a convenience sample of animals on a single farm at a single time point, so the extent to which the findings can be more widely generalised is unclear. CONCLUSIONS: The AUT system failed to detect animals classified as underconditioned by the operators and underestimated the condition of cows classified as overconditioned by the operators. Currently, without improvements to the algorithm, the clinical usefulness of such an AUT system for body condition scoring is limited.

Assessing the effects of weekly preweaning health scores on dairy calf mortality and productivity parameters: cohort study.

A longitudinal cohort study was conducted to follow the health of 787 calves from one UK dairy farm over a two-and-a-half-year period. Weekly health scores were gathered using a modified version of the Wisconsin Calf Scoring system (which did not record ear position) until calves were eight weeks of age, combined with data on colostral passive transfer, mortality, age at first conception and 305-day milk yield. High morbidity levels were detected, with 87 per cent of calves experiencing at least one clinically significant event (diarrhoea, pyrexia, pneumonia, nasal or ocular discharge, navel ill or joint ill). High rectal temperature, diarrhoea and a cough were the most prevalent findings. The effect of total protein levels was significantly associated with the development of pyrexia as a preweaning calf (P<0.01), but no other clinical health scores. The majority of moribund calves had just one clinically severe clinical sign detected at each of the weekly recordings. The overall mortality rate was 21.5 per cent up to 14 months of age, with 12.7 per cent of calves dying during the preweaning period. However, most calves that died were not recorded as having experienced a severe clinical sign in the time between birth and death, indicating a limitation in weekly calf scoring in detecting acute disease leading to death. Therefore, more frequent calf scoring or use of technology for continuous calf monitoring on farms is required to reduce mortality on farms with high disease incidence rates.