Browsing by Author "Schwartzkopf-Genswein, Karen"

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    Characterization of the hoof bacterial communities in feedlot cattle affected with digital dermatitis, foot rot or both using a surface swab technique
    (2024-01-22) Wong, Nicholas S. T.; Malmuthge, Nilusha; Gellatly, Désirée; Nordi, Wiolene M.; Alexander, Trevor W.; Ortega Polo, Rodrigo; Janzen, Eugene; Schwartzkopf-Genswein, Karen; Jelinski, Murray
    Abstract Background Lameness is defined as altered or abnormal gait due to dysfunction of the locomotor system, and is a health issue of feedlot cattle, having major economic, labour, and welfare implications. Digital dermatitis (DD—a lesion of the plantar surface of the foot) and foot rot (FR—affects the interdigital cleft) are common infectious causes of lameness in feedlots. These hoof lesions can occur alone or in combination (DD + FR) in the same hoof. A total of 208 hoof swabs were collected from three commercial feedlots located in southern Alberta. Every lesion sample was matched with a corresponding control skin sample taken from a healthy contralateral foot. Control skin samples were also collected from cattle with no lesion on any feet. Bacterial communities of three types of hoof lesions (DD, DD + FR, FR) and healthy skin were profiled using 16S amplicon sequencing. Results Alpha diversity analysis revealed a lower bacterial diversity on DD and FR lesions compared to control skin. Beta diversity analysis showed that bacterial communities of DD, FR, and DD + FR lesions were distinct from those of the control skin. While the impact of feedlot was minimal, lesion type contributed to 22% of the variation observed among bacterial communities (PERMANOVA-R = 0.22, P < 0.01). Compared to the corresponding control skin, there were 11, 12, and 3 differentially abundant (DA) bacterial genera in DD, DD + FR, and FR lesions, respectively. Conclusions The bacterial community description of a DD + FR lesion is a novel finding. Not only did lesions lead to altered bacterial communities when compared to healthy skin, but the composition of those communities also differed depending on the hoof lesion. The 16S amplicon sequencing of surface swabs has significant value as a research tool in separating different hoof lesions and can provide additional insights to the polybacterial etiology of DD and FR in feedlot cattle.
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    Prevalence, risk factors, and economic costs of beef cattle lameness in southern Alberta feedlots
    (2018-01-25) Davis-Unger, Jessica; Orsel, Karin; Schwartzkopf-Genswein, Karen; Pajor, Ed
    Lameness, an important health and welfare concern with negative impacts on production, performance, and profitability of feedlot cattle is a multi-faceted issue that is not fully understood. Objectives were to identify the prevalence of lameness, related risk factors, explore associations between BRD and lameness, and estimate net return of various lameness diagnoses. Estimated lameness prevalence was 32% (range, 1.3 to 46%) from cattle health records at 28 feedlots from 2005 to 2015. Fall-placed calves were more at risk of lameness with no swelling compared to yearling cattle that were at risk of foot rot diagnosis. Heifers were at a higher risk of lameness compared to steer cattle types. Cattle with chronic lameness were at a higher risk of subsequently developing BRD. Furthermore, cattle with joint infections and lameness with no swelling had negative returns of $-286 and $-701, respectively. Therefore, lameness was a common and costly disorder in Alberta feedlots.