Discipline: lameness; Keywords: claw health, dirt lot, free stall, sole ulcer, white line.
Claw health is an important factor in animal welfare and its evaluation is an early indicator of lameness in dairy cattle. However, claw disorders on many farms are not routinely evaluated and the information not included in genetic evaluations as they are not always considered in terms of productivity. The aim of the study by the authors cited below was to evaluate claw health of dairy cattle housed in dirt lot vs free stall under the TMR systems.
The study involved nine commercial dairy farms having a dirt lot or free stall system. Data was collected during trimming, by professional claw trimmers from January 2011 to May 2018 and recorded on lesion recording sheets. The initial lesion data contained a total number of 24 887 claw disorders from 48 993 cows. The scored claw disorders were heel erosion (E), digital dermatitis (DD), foot rot (F), hairy attack (HA), axial fissure (AX), sole ulcer (U), toe ulcer (TU), white line (WL), sole fracture (SF) and corkscrew (C). Data from 34 526 cows and 12 309 claw disorders was statistically analysed for year, season and dirt lot vs free stall variables.
No significant differences (P > 0.05) were observed for DD, HA, SF and across years and farms. Significant differences (P < 0.05) were present for C in 2014 and 2015 for all farms. Significant differences were also observed in 2014 for F, U, AX, TU and WL, and the highest frequencies were observed in 2014 and 2018 for WL (6.5%) and E (11%) respectively. Season had no significant effect (P > 0.05) on the prevalence of DD, SF and AX, but a higher frequency of C (8.4%), WL ( 3.3%) and HA (1,2%) lesions was observed in winter, autumn and summer. Significant differences (P > 0.05) in F between autumn and spring were recorded, with F (3.8%) being more prevalent in autumn. Autumn had an effect (P < 0.05) on U and TU. For E a significant effect (P < 0.05) was observed across all seasons. Free stall and dirt lot farms had no significant effect (P > 0.05) on DD. The frequency of E (10.0%) and U (3.5%) was high in the free stall system. WL, AX, HA and F were significantly (P < 0.05) affected by both systems, with dirt lot having the highest incidence. No significant differences (P > 0.05) were observed for TU, SF and C in both systems.
The study suggested that season and housing system have marked effects on the prevalence of claw lesions. The finding is thus suggestive of the influence of the factors studied in the incidence of lameness, with different lesion type having significantly different risk factors. Thus, improved management and housing systems may result in significantly decreased incidence of lameness in dairy cows.
N.L. Mhlongo, J. Tucker & E. van Marle-Koster, 2019. Evaluation of claw health of dairy cattle housed in dirt lot vs free stall in TMR systems in the central regions of South Africa. In: Proc. of the 51st Annual SASAS Congr., Bloemfontein, 10-12 June 2019, Abstract 108.