I've been summoned! (This is not my area of expertise, but I learn quickly, and have reason to do so. More I'm a good researcher, and am motivated by need).
I assume you mean
Bidens Pelosa? (with the forked seed pod that sticks to damn near everything, velcro like???) Its actually a forage (and not technically a grass) which used to be far more popular in the past than today - its mentioned by Laura Ingalls-Wilder in Little House on the Prarie, actually. Related to Asters, its an attractant for a number of beneficial insects, and quite successful at securing (and breaking up) the top inch or so of clay soils against runoff. Also somewhat shade tolerant, it likes rain, and is salt tolerant. The stems and leaves are NOT frost tolerant, but it takes a very hard freeze to kill the roots, not the sort of thing seen in Central and South FL, I fear.
This is a pretty good data sheet on it.
I have some on my property at present, though not a lot - and removed a clump on the path from the RV to the outdoor shower earlier this week. I've flagged it mentally as a "Caution" plant which requires aggressive, but not immediate, management - because its hard to control once well established, not because of any toxicity concerns.
Anyhow, coming back to the original question. It USED to be a popular forage, and is particularly valued by horses. Cattle tend to ignore it, but will eat it cut. Some chickens love it, I've not noticed mine paying it much attention, but I have so little i may have overlooked their grazing it. I can confirm they do, occasionally, eat it - they just don't strip it bare. Same with the goats - like cattle, I assume they would eat it cut, but my goats prefer blackberry brambles over everything else I've offered them. Humans can eat it too, the flowers and also the very young leaves, raw - while older leaves and stems should be cooked.
Here are a
few choice
links regarding
its use as forage (read this one) and/or cover crop. I can't find much information on its nutritional make-up - this is a link to
a source I don't normally rely on (table 3) which indicates its actually, apart from the moderately high fat content, a better than typical chicken feed. It seems to be preferred early season, before the seed pods grow and harden off, while the plant is still tender.
Compared to other green leafies, a near 16% protein content (other sources put it as high as 24%, dried) is quite good, 7.5% fat is high but may be useful during the heat of late summer as calorie source, since it doesn't require metablic activity to process as a carbohydrate does, and its got a lot of fiber (and that's why its prefered by horses, or dried forage for cows and goats). The Methionine and Lysine numbers are in line with a chicken's needs, and the Tryptophan is high enough that this can compensate (in part) for other (low tryptophan) feed sources like corn. I've seen no threonine listing, that's a limiting amino acid in grains, so if your feed is mostly corn, wheat, barley, this won't fix that.
On the vitamin side, this is a really good source of calcium and vitamin C, and a worthless source of B vitamins.
I will say that the plant is also alleged to have numerous medicinal properties, but studies supporting same (as with many folk medicines) are remarkably sparse. And for good or ill, some of the compounds in this plant are strongly phototoxic, meaning they are dangerous in the presence of sunlight, so this isn't the sort of stuff you would normally want to rub on bare skin....
Hope that helps.