Risk factors for claw disorders in intensively finished Charolais beef cattle

Abstract

This cross-sectional study aimed at performing a risk factor analysis of on-farm housing and management factors associated with infectious and non-infectious claw disorders of intensively finished Charolais young bulls and heifers. Claws' health condition of a total of 1305 animals belonging to 88 batches finished in farms located in the Eastern Po Valley (Italy) was assessed at slaughterhouse. Batch prevalence of feet affected by sole hemorrhage (SH) and white line abscess (WLA) was calculated and foot condition was summarized by infectious lesion (ILS) and non-infectious lesion (NILS) scores according to diseases' etiology. Batch prevalence of feet with SH, WLA, and assigned to the worst score classes were the outcomes in the risk factor analysis. Information about rearing facilities and health management of the tested batches were gathered in each origin farm along with a dietary sample used for chemical and physical analyses. Five categorized factors and 30 continuous covariates were considered as independent predictors and a cluster analysis of the continuous covariates was performed to select the most representative ones. Percentage of feet/batch affected by SH was on average 57.0 ± 32.5 % (SD) and by WLA was 9.94 ± 12.7 %. Percentage of feet/batch with the worst ILS and NILS was 29.6 ± 32.8 % and 12.5 ± 14.1 %, respectively. Charolais bulls showed a higher risk of SH and WLA than heifers and an increasing dietary NDF content acted as preventive factor. Concrete slats increased the risk of SH. Animals slaughtered in winter had the highest risk of WLA and the increasing level of dietary water-soluble carbohydrates (WSC) was a further risk factor. The risk for the worst NILS was lowest in spring and in presence of ventilation systems. It increased for bulls and in those batches fed diets with higher WSC content. Batches for which the farmer reported a higher prevalence of urgently slaughtered animals during finishing showed a higher risk of WLA and infectious claw diseases. The risk for infectious claw diseases was reduced in animals slaughtered in summer, housed on deep litter and fed diet with increased NDF content. It increased in farms where diet formulation was not under the nutritionist control. As general outcomes of the study, benefits for the claw health of finishing Charolaise may come from the use of the deep litter and ventilation systems, the involvement of a nutritionist in diet formulation, and the provision of diets with reduced WSC and increased NDF contents.

Keywords: Beef cattle; Charolaise; Claw disorder; Intensive fattening system; Risk factor analysis.