Sustained diuretic effect of plantain when ingested by sheep

Abstract

Narrow-leaved plantain (Plantago lanceloata L.) was investigated for its potential to act as a diuretic in sheep.For seven days, two groups of sheep (n=8) were provided with either ryegrass or plantain diets that had similar water content. Dry matter in feed, fresh faecal weight, and faecal water content was measured daily, as well as volume, specific gravity and osmolality of urine. Urine volumes on Day 1 of the trial were significantly different to those of Days 2-6 of the trial (P < 0.05) so the results were analysed separately. Plantain sheep had a higher volume of urine (by 1.7 L, P < 0.05) on Day 1 than Ryegrass sheep and continued to pro-duce about 0.5 L more urine each day than Ryegrass sheep for the remainder of the study period. Because intakes of feed and feed water content for the two diets were essentially equal, this study provides the first direct evidence to show that plantain causes a diuresis when it is ingested by sheep, possibly by reducing reabsorption of water in the kidneys.