A method for obtaining abomasal fluid via a rumen fistula.

Abomasal fluid was collected from adult cows using a specially designed tube device. The device was placed in the abomasum through a rumen fistula. A filter on the end of the tube filtered out the larger particles so the liquid could be aspirated up a smaller tube placed inside a larger one. The smaller tube reduced the amount of dead space created by the distance from the abomasum to the rumen fistula.