Relationship between lameness and milk production in Italian Friesian cows under scheduled hoof trimming

The aim of our study was to investigate the possible milk loss caused by lameness in Italian Friesian cows. Data from a scheduled hoof-trimming programme were collected between January 1997 and December 1998 in 26 dairy herds and joined with test day milk yield (TD) records collected during the same period. The no. of TD and correspondingly health or lameness diagnosis (HLD) ranged from 2910 (at 1st TD) to 1284 (at 10th TD). The milk differences between subsequent TD for healthy (H) or lame (L) cows diagnosed in between were analysed. There were significant milk losses in primiparous L cows than in H animals before the peak of lactation (-1.5 kg/d; P=0.06) and in late lactation (-1.8 kg/d; P=0.02). Lame first parity cows produced 355 kg less milk than H primiparous over a 305 d lactation period, i.e. about 1.2 kg/d. However, L cows in parity 2 or parity 3 had a higher mean milk production than H animals over a complete lactation (+1.0 kg/d and +1.4 kg/d, respectively). In conclusion, lameness showed a negative effect on primiparous milk production, but not in older cows.