Impact of digital dermatitis on the behaviour, locomotion, and welfare of beef cattle (Bos taurus)
Date
2022-01-06
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Abstract
Digital dermatitis (DD) is an infectious disease affecting feet of cattle, a major cause of lameness, significantly impacting productivity and welfare. DD’s emergence in feedlots and its impact on the behaviour and welfare of feedlot cattle is not well understood. This thesis’s aim was to understand the initiation of DD in beef cattle, and its impact on behaviour and welfare. Two studies were conducted, a field study and an experimental study. Impact of DD on behaviour was measured by way of an ear accelerometer and through video recordings, pain and inflammation was assessed with an algometer and infrared camera. Behaviour changes 5 to 2 days before DD diagnosis in heifers. Rumination is depressed, 3% less per day, and inactivity increased, 3% more per day, in heifers afflicted with DD compared to heifers without lesions. Further, daily mean time ruminating was 5% less in cattle with active lesions compared to heifers without lesions. Pain (mechanical nociceptive threshold; MNT), and inflammation (maximum foot temperature; MFT) were measured at the lesion site. MNT was significantly less in feet with DD lesions. MNT was lowest in active lesions, which withstood 8 N and 4 N less pressure than feet without lesions and feet with chronic lesions respectively. A 1 °C increase in MFT was associated with a 0.6 N decrease in MNT. Higher MFT was associated with feet with DD lesions and increased when cattle were lame. Cattle with DD were determined to be more likely to be lame and have altered gait compared to cattle without lesions. Locomotion score, reluctance to bear weight and asymmetric gait were determined to be most predictive of cattle with DD. The final chapter of this thesis describes an experimental model that was used to successfully induce DD lesions in beef calves. An induction rate of 60% was realised within 28 days. Overall, this thesis increased scientific knowledge on the impact of DD on beef cattle, induction, impact on behaviour and locomotion, and pain implications. This thesis provides information that would be useful when developing strategies for early detection, diagnosis of DD and when conducting intervention studies.
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Keywords
beef cattle, behaviour, pain, lameness, experimental model, hairy heel warts
Citation
Thomas, A. D. (2022). Impact of digital dermatitis on the behaviour, locomotion, and welfare of beef cattle (Bos taurus) (Doctoral thesis). University of Calgary, Calgary, Canada). Retrieved from https://prism.ucalgary.ca .