a1 Teagasc, Moorepark Dairy Production Research Centre, Fermoy, Co. Cork, Ireland
a2 School of Agriculture, Food Science and Veterinary Medicine, UCD, Belfield, Dublin 4, Ireland
The aim of the present study was to determine the effect of the genetic group of the Holstein–Friesian (HF) and pasture-based feeding system (3 × 2 factorial arrangement) on locomotion score (six gait aspects scored from one to five), clinical lameness and hoof disorders within a seasonal calving milk production system. The three genetic groups compared had an average Economic Breeding Index (EBI) value of 40, 70 and 80: representing the Irish national average genetic merit (LOW-NA), high EBI genetic merit of North American ancestry (HIGH-NA) and high EBI genetic merit of New Zealand ancestry (HIGH-NZ), respectively. Two feed systems were compared: a high grass allowance, low-concentrate system typical of spring-calving herds in Ireland (control) and a high-concentrate system. Data from 126 cows collected across a complete lactation period were analysed using generalised estimating equations and survival analysis. Genetic group of HF had a significant effect on locomotion score, clinical lameness and hoof disorders. Higher EBI cows (HIGH-NA and HIGH-NZ) had lower hazard of poor locomotion score in some gait aspects (e.g. spine curvature) and lower odds of clinical lameness in the first 200 days post-calving (Odds ratios 0.08 and 0.24, respectively, relative to the LOW-NA) and some hoof disorders (e.g. traumatic lesions) compared with LOW-NA cows. The high-concentrate feed system showed a higher incidence and severity of digital dermatitis (P < 0.01). Thus, high EBI cows have better locomotion, fewer cases of clinical lameness and less-severe hoof disorders (i.e. digital dermatitis, white line disease and traumatic lesions) than low EBI cows. These findings have important implications for cow welfare and productivity.
(Received December 07 2007)
(Accepted August 18 2008)