Influence of saline drinking water on mineral balances in sheep

Abstract

The influence of sodium chloride ingestion via the drinking water upon the mineral balance in sheep has been examined. Four Merino ewes were offered rainwater containing zero, 0.8, or 1.3 % sodium chloride as the only source of drinking water. After correction for variations in mineral intake, the data showed that the urinary excretion of calcium, magnesium, potassium, phosphorus, sodium, and chloride was increased by saline water ingestion. The faecal excretion of calcium, magnesium, and phosphorus was not affected by the inclusion of sodium chloride in the drinking water, but faecal potassium was decreased and sodium and chloride increased. The drinking of saline water by the sheep resulted in a decline in the calcium, phosphorus, and potassium balances, an increase in the sodium and chloride balances, and no change in the magnesium balance. The sodium balance was negative for the rainwater treatment, but all other balances were positive. Saline water ingestion also caused an increase in the glomerular filtration rate, a decline in plasma magnesium levels, and an increase in plasma potassium levels. It is concluded that saline water ingestion causes alterations in the pathways of excretion of minerals and the mineral balances in sheep, but the changes would appear to be of insufficient consequence to have detrimental effects.