Relationship between liver and blood plasma copper level and abortion in cattle

Copper is a component of a number of metalloenzymes. Copper deficiency is endemic in ruminants worldwide and causes diseases of economic importance. Blood plasma samples were collected from 318 cows (198 aborting and 120 recently calved cows) originating from 16 commercial Holstein dairy herds in southeast Iran. Liver samples were taken from 76 cows (64 aborting and 12 recently calved cows) from a total of 318 followed cases. Liver copper concentrations of aborting cows are lower than 20 mg/kg DM (the marginally deficient status) in all of the slaughtered cows except two cases (96.875%) and all of 12 samples of recently calved cows, which were followed, had liver copper concentrations between 15 and 20 mg/kg DM. If we consider 20 mg/kg DM as the threshold level of liver copper, therefore serum copper concentration =9 mmol/L will be a good indicator of copper deficient status. The results of the present study show that plasma copper concentration of aborting cows is significantly lower than recently calved cows (p < 0.05). Results of the evaluation of plasma copper concentrations show that 87.87% of aborting cows and 11.67% of recently calved cows are copper deficient. Based on the results of present study it seems that copper deficiency has close relationship with abortion in cattle. To prevent the economic loss due to hypocuprosis, early treatment of positive cows is necessary and prevention of the abortion has to be achieved through proper nutritional programs during gestation.