The Relationship among Total Dissolved Solid in Water and Blood Macro Mineral Concentrations and Health Status of Dairy Cattle in Qom Area

Dairy farms in some arid areas around the world have to use drinking water that contained elevated total dissolved solids (TDS); however, very limited data is available concerning water TDS effects on health status and blood mineral levels of cattle. The aim of this study was to compare 3 dairy cattle groups in several dairy farms with different drinking water TDS: High (HTDS; >4000 ppm), Medium (MTDS; 1500-3000 ppm), and Low (LTDS; ≈ 490 ppm). Metabolic disorders record and some management information of each herd during five years were collected and some Holstein dairy herd in Qom (n = 10) were assigned to 3 groups. Moreover, six same dairy cows were selected from each TDS group and blood and feed samples were collected twice a week. Urine samples were taken from the dry cows and urine pH was measured. Data were analyzed using the MIXED procedure of SAS. Although water TDS range was between 500 and 4500 ppm, dry cows urine pH was unaltered by water TDS and health problems are not common in this area. Blood calcium concentrations increased linearly as TDS increased (P < 0.05). Similarly, blood potassium concentrations were affected by TDS, whereas blood Mg and Na contents were unaltered by TDS. Negligible elevated some mineral concentrations in blood whereas the water TDSs are dramatically different show necessity of revision of mineral supplementation or providing high quality water to decrease metabolic stress in dairy cattle.