Lameness of cows is an important factor influencing the longevity and performance of the herd, including milk yield losses. It has a negative impact on reproductive performance and constitutes an increasing risk for early culling. Claw disorders, such as white line diseases, sole ulcers or papillomatous digital dermatitis, are the most frequent causes of clinical lameness in dairy cows. Lameness most often appears within 100 days postpartum, and its incidence was calculated at 54.5 to 65% per 100 cows, whereas the mean prevalence of lameness has been estimated at 20.6%. Lame cows exhibit different oestrus behavior than non-lame cows. Above all, lame cows had a shorter oestrus, and an increased locomotion score was associated with a shorter time of standing and walking as a consequence of a longer time of lying down. A poor oestrus detection rate is likely to be a more important factor in reducing average fertility levels. Hence, the average conception rate and pregnancy rate for lame cows are lower, and the rates of services per conception are higher. Lame cows have a longer interval from calving to conception compared with non-lame cows. In the case of lame cows with lesions and multiple lesions this interval amounted to 140 and 170 days, respectively, as compared with 100 days for healthy cows. Ovarian cysts are observed in about 10-30% of lactating dairy cows and are more likely to occur within the first 80 days postpartum, i.e. during the same period when hoof disorders and lameness occur. Lameness in cows within the first 30 days postpartum was associated with a higher incidence of ovarian cysts, a lower likelihood of pregnancy and lower fertility than in non-lame cows. The effect of lameness on culling within the first 60 DIM was lower, but cows diagnosed in this period seemed to be at a greater risk of being culled between 121 and 240 DIM. Nevertheless, when deciding whether to cull a cow, one should consider such factors as parity, lactation stage, milk yield, reproductive performance, health, season and animal welfare.
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