Genetic and environmental components of metabolic diseases and lameness in cattle.

Metabolic diseases including displaced abomasum, ketosis, and lameness have substantial impact on the productivity of beef and dairy cattle herds. Laminitis has been associated to nutritional effects causing metabolic disorders. These diseases are more prevalent in dairy herds and their impact in production is more extreme in dairy cattle than in beef cattle. Therefore, the stronger signal of disease incidence in dairy herds offers a model to further the understanding of the factors influencing the incidence of these diseases in beef cattle. The objective of this study was to assess the impact of nongenetic and genetic factors on the incidence of displaced abomasum, lameness, and ketosis. Health records were analyzed from approximately 6,200 records from Holstein cows across 4 U.S. regions. Two indicators of these diseases were studied: binomial detection of at least 1 disease and multinomial detection of none, at least 1, and at least 2 diseases in 1 lactation. The fixed effects explanatory variables included parity, season, milk yield level (high and low), region, and BCS, and sire was included as a random effect. Parity, season, and milk yield level had significant effects on both disease indicators. The binomial probability of disease and the multinomial probability of multiple diseases were higher with higher parity, in summer relative to winter, and in high producing cows relative to low producing cows. The heritability estimates of the binomial and multinomial disease indicators were 0.28 and 0.3, respectively. The heritability estimates for incidences of displaced abomasum, lameness, and ketosis were 0.33, 0.16, and 0.19, respectively. Our findings suggest that the 3 diseases share both the nongenetic and genetic components and that management practices and genetic selection to reduce the incidence of 1 or 2 of these diseases will reduce the incidence of the remainder diseases. These findings contribute to an animal health project (USDANIFAILLU538909) and a multistate project database (USDANIFAAFRI003542) for direct measures of health and fertility in cattle. [ABSTRACT FROM AUTHOR]