Studies on salt tolerance of sheep. VI. The tolerance of wethers in pens for drinking waters of the types obtained from underground sources in Australia

Abstract

Seven groups, each of six wether sheep, were fed in pens for 15 months on a ration of chaffed lucerne and wheaten hays and were offered various solutions as drinking waters. These comprised: (1) rain-water (control group); (2) 1.30% sodium chloride; (3) and (4) synthetic waters containing salts in the proportions found in many underground waters in South and Western Australia (referred to in this paper as "chloride waters"), with total concentrations of 0.65 and 1.30% respectively; (5) and (6) synthetic waters resembling those obtained in Queensland from the Great Artesian Basin ("bicarbonate waters"), with total salt concentrations of 0.20 and 0.50% respectively; and (7) sea-water diluted with rain-water to a total salt concentration of 1.30%

The intake of all saline solutions, except that of the bicarbonate water with a concentration of 0.20% salts, was higher than that of rain-water, the increases ranging from 80% for 1.30% sodium chloride to 15% for the more concentrated bicarbonate water. The intake also increased in all groups with temperature, being 40-90 % higher in the hottest months than in the coldest months.

Compared with the control group a significant decrease in wool production was observed only in the group receiving bicarbonate water with 0.50% total salts. These sheep also produced significantly less wool, for at least a portion of the experiment, than did those receiving the other synthetic mixtures of salts.

The concentrations of potassium, calcium, and chloride in the blood plasma were not affected by the saline drinking waters. The concentrations of sodium at times were higher in the plasma of the control group and lower in the plasma of group 2 (1.30% sodium chloride) than in that of the remaining groups. Magnesium concentrations at times were higher in group 7 (diluted sea-water) and lower in group 2 than in the remaining groups.

None of the solutions used in the experiment had any adverse effect on general health, food consumption, or weight increase.