Comparison of the weight gain and the composition of blood and saliva in sheep grazing timothy and ryegrass swards.

I . After a preliminary period of z weeks indoor feeding on hay, two groups of wethers grazed either a timothy pasture or a ryegrass-dominant pasture for 12 weeks. The timothy was particularly low in sodium and chlorine. 2. Within a week of turning out, saliva sodium fell and potassium increased in the timothy group, and by the end of the experiment, the sodium:potassium ratio was 1.9: I . The changes in saliva were not reflected in blood composition. The rate of live-weight gain was similar in both groups of sheep. 3. The results confirm those of a previous indoor experiment and show that timothy supplies insufficient sodium to maintain the normal saliva composition of sheep.