Mineral Status of Cattle in the San Carlos Region of Costa Rica

Abstract

Two experiments on 12 beef and 9 dairy cattle farms were to determine the mineral status of grazing cattle in the San Carlos region of Costa Rica by evaluating concentrations of minerals in liver, plasma, bone ash, forages, and oxalate contents of forages.Copper (<75ppm) and cobalt (<.07ppm) in liver, and phosphorus (<4.5 mg/100ml) and magnesium (<1.8 mg/100ml) of plasma were borderline to deficient on 1, 3, 12, and 5 beef cattle farms, respectively. Of livers, 23% and 27% were borderline to deficient in copper and cobalt. Iron (<180ppm), zinc (<84ppm), and manganese (<6ppm) in liver were lower than normal for 63, 16, and 44%, respectively, of the animals.In dairy cattle, 10 samples of blood and 1 to 2 of forage were collected on each of 5 farms with and 4 farms without the forage Setaria sphacelata. Calcium (.29%) and phosphorus (.18%) concentrations in forage were low in relation to requirements of lactating dairy cows. Phosphorus in plasma was deficient (<4.5 mg/100ml) on all farms. Oxalate percentages were higher in Setaria pastures (2.30%) than in other pastures (1.24%). Low calcium and phosphorus in forage and high oxalate in Setaria pastures may be responsible for the high incidence of a milk fever-like condition in dairy cattle.