Case-control study of mineral concentrations of hoof horn tissue derived from feedlot cattle with toe tip necrosis syndrome (toe necrosis).

This study determined whether mineral concentrations in the hooves of cattle with toe tip necrosis syndrome (cases) differed from those of cattle dying of all other causes (controls). Samples were collected over a 2-year period from 16 different feedlots and analyzed for 8 minerals [cobalt (Co), copper (Cu), iron (Fe), magnesium (Mg), manganese (Mn), molybdenum (Mo), selenium (Se), and zinc (Zn)]. Mineral concentrations in the hoof wall and solar horn of the same hoof were poorly correlated; Se was the most correlated (ρ = 0.865; P < 0.001), while Mg (ρ = 0.465; P < 0.001) and Zn (ρ = 0.157; P = 0.053) were the least correlated. The cases had significantly lower Mg concentrations in both the hoof wall and solar horn tissue compared to the control subjects. For every 10 ppm decrease in Mg, the odds of a diagnosis of toe tip necrosis syndrome (TTNS) increased by 1.13 times for the hoof wall ( P = 0.002) and 1.21 times for solar horn ( P < 0.001).