The aim of this study was to investigate the relationship between lameness and reproductive performance in dairy cows. A retrospective case-control study was conducted at 20 farms in 326 cows with high prevalence (>30%) and at 20 farms in 331 cows with low prevalence (<10%) of lameness. Cows having a locomotion score ≥3 were classified as lame. Reproductive data were collected and analyzed. Calving to calving interval, calving to first service interval, services per conception, and pregnancy rate in lame cows were poorer than non-lame cows (P<0.05). The severity of reproductive consequences was greater in high prevalence farms than in low prevalence farms. Cows classified as lame were 3.5 times more likely to be non-pregnant compared with non-lame cows (P=0.0001). Attributable proportion analysis indicated that non-pregnancy in lame cows could have been reduced by 70% if lameness had been prevented.
