What part do you feed to the poultry and how do you feed it?
From Wikipedia: Many parts of the Typha plant are edible to humans. The starchy rhizomes are nutritious with a protein content comparable to that of maize or rice. They can be processed into a flour with 266 kcal per 100 grams. They are most often harvested from late autumn to early spring. They are fibrous, and the starch must be scraped or sucked from the tough fibers. Plants growing in polluted water can accumulate lead and pesticide residues in their rhizomes, and these should not be eaten.
The outer portion of young plants can be peeled and the heart can be eaten raw or boiled and eaten like asparagus. This food has been popular among the Cossacks in Russia, and has been called "Cossack asparagus". The leaf bases can be eaten raw or cooked, especially in late spring when they are young and tender. In early summer the sheath can be removed from the developing green flower spike, which can then be boiled and eaten like corn on the cob. In mid-summer when the male flowers are mature, the pollen can be collected and used as a flour supplement or thickener.
The seeds have a high linoleic acid content and can be used to feed cattle and chickens.