Effect of high intakes of sodium chloride on the utilization of a protein concentrate by sheep. II.* Digestion and absorption of organic matter and electrolytes

Abstract

The effects of the ingestion of large amounts of sodium chloride (c. 150 g/day) on digestion and absorption were examined in sheep offered a diet consisting of 89% linseed meal. Although water intake was increased by only 2 litres per day, the rate of flow of fluid from the rumen and digesta from the abomasum increased by 5–6 kg/day and the mean residence time of a soluble marker was reduced from 20 hr to 12 hr. Digestion of organic matter in the stomach was reduced by c. 24% but the reduction in protein digestion was only 10%. The concentrations of protozoa and selenomonads in the rumen were reduced by the salt treatment.

Approximately 50% of the ingested sodium and chloride was absorbed from the stomach in sheep on the high salt diet, although levels of sodium and chloride in the rumen did not exceed those in the plasma. Osmotic pressures in the stomach fluids and in the plasma were elevated by the salt treatment, although levels of sodium in plasma were unaffected. Plasma chloride and potassium levels were both increased by the salt treatment.

*Part I, Aust. J. Agric. Res., 26: 709 (1975)