They give a breakdown of what is in it if you scroll down. They are selling pots of seedlings. It would be very expensive to plant even a small
chicken run.
You can easily buy the seeds and do the same yourself for a fraction of the cost.
A couple of clovers, a little Fat Hen, and some
flax if you want the omega-3 content. Chickens like humans and other animals do best with a varied diet.