Hi, I don't have chickens but I do have dogs and I've used this product and I'm VERY happy with the results. I live in Wisconsin. I started by looking up organic fertilizers, and came across a lot of good feedback on Cockadoodle Doo on the internet, so I thought I'd give it a try.
When we first purchased our home, our lawn was awful. We did some landscaping in our back yard, and the grass was so weak that we could easily pull it out by hand. We watered, weeded, used the typical weed killers that we purchased at a local home improvement store and our lawn never improved.
Last year, we started using the weed control and the fertilizer. You apply them 60 days apart, and keep alternating. This year, our lawn came up green and lush. We were doing some more landscaping and tried pulling some grass out by hand - no way - it is so strong we had to rent a tiller.
The weed control works well too. We don't have as many weeds this year, but the way it works is that the fertilizer makes your grass so strong that it can't be taken over by weeds. The more you use it, the stronger and better your lawn will get. I love this product. I had to drive 50 minutes out of the city to get it this year because the only store in my area was sold out - some guy came in and purchased every bag they had.
I also have dogs, so using something organic is very important to me.
One other thing - the first couple of years that we were here we used typical store brand weed & feed for our lawn. We live in the city in a nice, upscale residential area. While using the non-organic products, we had several dead birds on our lawn, and a dead rat (yes, a rat!) within weeks of eachother. At first we thought maybe the birds were due to the West Nile Virus (or whatever virus it is that birds carry), but I really think it was the chemical weed killers that we were using, because it was like clockwork. We'd apply the stuff to our lawns, and soon we'd find a dead bird. My husband was also seeding the lawn at that time too, so the birds were probably feeding on the seed, and poisoning themselves in the process. I don't know about the rat. But, kind of scary that they sell stuff for your lawns that is that toxic to our environment. I never drink tap water, needless to say. In any case, since we started using Cockadoodle Doo, no problems with dead birds or animals. Is there a correlation? I can't say for sure, but it's just my opinion and I'd rather err on the safe side.
Good luck in whatever you decide.