composted manure only, this goes for any manures, especially chicken. If it hasn't been actively composted and just was sitting in a pile I'd say a year old. My neighbors have horse stables and brought manure for my veg garden and I'd leave it until the following spring. Now I have my own composter so I don't get the manure delivered any more.
25% compost is a good amount, no more than that. The best thing you can do, in my opinion is to till the soil deep and wide.

Good info from good people HERE
Shovelhandle Reviewed by Shovelhandle on . Cow Manure Howdy Folks ! I found his forum a couple weeks ago and have been browsing as I have time (Great Forum!) I see that allot of you folks put allot of effort into your grows, but I see little mentioned abot cow manure, what gives? I have not grown in about 20 years but have started my holes already for next spring, with plans for a major effort. Back in the day I used cow manure and had no problems growing plants 10 to 15 foot tall, I am putting this in my holes now with 50 50 dirt/manure for Rating: 5