Abstract
During the winter of 1956–57 a series of grazing trials was conducted on the desert of west-central Utah to determine the practicability of using sheep equipped with esophageal-fistula cannulae for collecting diet samples. The fistulated animals were grazed in inclosures for trial periods of six to eight days. There were seven such trials, each located on a different vegetation type. Diet samples were collected daily from the animals and analyzed chemically. Diets for each trial were also determined by hand plucking vegetation samples representative of the forage being consumed. A comparison of the chemical content of diets obtained by fistula and hand plucking shows differences to be statistically significant for all constituents except ether extract, total protein, and cellulose. The greatest differences were found in ash and phosphorus. Correcting the fistula samples for ash and phosphorus contributed by saliva during collection is desirable even though the nutritive content is changed only slightly. Copyright © . .