Medycyna Wet. 66 (12), 818-821, 2010
Olechnowicz J., Jaœśkowski J. M.
Incidence and prevalence of lameness and their relationship to milk yield in high-yielding cows
The aim of this study was to present, on the basis of results of the conducted research, associations of clinical lameness with milk yield in cows. Lameness in dairy cows is an important disease with a multifactorial etiology and represents one of the three most common health problems, after infertility and mastits. Currently it is the reason for an increasing risk of culling in dairy cows, especially in high yielding herds. The incidence of lameness was from 2.1% to 50% per 100 cows. Some studies indicated that the incidence of lameness increases with lactation rank, while others do not state a significant effect of parity on lameness incidence. The prevalence of lameness ranged from 5% to 24.6%. The main factors influencing the prevalence of lameness in dairy cows include calendar season of the year, comfort of stalls, hoof trimming frequency and the presence of concrete floors. The main causes of diagnosed lameness include sole ulcers (SU), white line diseases (WLD), interdigital necrobacillosis (IN) and digital dermatitis (DD). Results reported in literature indicate considerable differences in the incidence of clinical lameness (CL) in dairy cows, from 2.1 to 50%. This is associated with difficulties in its definition and identification in cows. Many authors reported that CL is associated with decreased milk production by lame cows, especially in the initial period of lactation. Some data indicate a reduced milk yield through lactation in clinically lame high-yielding cows, amounting to 574 for SU and 369 kg for WLD. Cows culled due to foot disorders had daily milk, fat and protein yields significantly lower by 11.3, 14.1, and 16.4%, respectively. Other authors found no association between lameness and milk yield, while some are of the opinion that this relationship occurs only during mid- and late lactation. Several authors reported that the effect of claw and limb disorders on milk yield is not direct, since many factors influence milk production, e.g. feeding routine and nutrition. The use of different statistical analyses in the elaboration of data may lead to different results.
Keywords: incidence and prevalence of lameness, cow, clinical lameness, milk yield, high yielding herds