Determination of the level of comorbidity and assessment of the effect of orthopedic pathologies on basic production indicators of cattle

The aim of the study was to identify the spread of hoof diseases among cattle in industrial complexes, to determine the level of comorbidity and to establish the degree of the effect of limb diseases on production and economic indicators of cattle. The studies were conducted in the period from 2018 to 2020 in two industrial complexes in the south of Tyumen region, and on the largest dairy cattle farm in Central Russia. A total of 11 602 heads of the dairy cattle were taken for clinical examination.

Orthopedic pathologies of cattle on the surveyed farms were on average widespread in 8.5% of the livestock, and hoof disease related culling of animals was 6.67±2.35%. The most common diseases are laminitis (27.0±4.38%), purulent pododermatitis (10.33±2.18%), Mortellaro disease (14.17±5.15%), interdigital dermatitis (8.37±1.15 %), and Rustergoltz ulcer (10.77±1.80%). According to the 5-point lameness scoring system proposed by D.D. Sprecher, severe cases of lameness were recorded in 10.28±0.98% of affected animals. Moderate lameness (3 points) was observed in 19.20±1.53% of animals, and weak lameness was diagnosed in 15.18±0.57% of sick animals. According to the Karl Burgi and Nigel B. Cook scale, 44.19±1.07% of cattle had a mild lesion, moderate severity was recorded in 21.88±2.78% of animals, and a severe lesion was found in 33.93±2.09% of animals. Culling of animals with musculoskeletal pathologies attained 8.48±3.04%.

Direct relationship was established between the severity of hoof lesions, the probability of comorbidity and associated pathology. It was revealed that the main indicators of production and fertility decrease due to hoof diseases, which is associated with a high level of comorbidity and accompanying gynecological diseases in addition to the main disease, delayed estrus, general decrease in the immune resistance and lack of the optimal correspondence between biological and necessary technological rhythms. The limb disease has a particular effect on fertility and reduces its level to 16% of the average fertility rate in the herd, affects manifestation of estrus (up to 48% of affected animals do not show signs of estrus), average milk production (decrease to 22 kg/day during the first lactation and to 28 kg/day during the second lactation in dairy herd with an average daily production of 32 kg/day, 38 kg/day, respectively), and the number of somatic cells in milk (increase up to 150–430 thousand units/ml).