The sheep manure may be quite 'hot', and DEFINITELY is too rich for seedlings. Hang on to it for later.
You can try out those peat pucks for starting seedlings- they do hold a lot of water, so be careful about that, but they'll work okay. Just shred the mesh a little before you plant them.
REmember plants don't want fertilizer of any sort until they are on their 5th set of true leaves.