What is well rotted manure?
Ideally, yes. What is sold as well rotten manure is manure that is old and weathered. While this may have washed out excess salts, true composting hasn’t occurred. Manure by itsself doesn’t make a good compost……oh well, maybe horse if there’s some bedding in the mix. Generally manure is too high in “green material” and doesn’t have the “brown” or carbohydrate/bulk material needed to get a good aerated decomposition. If the source is nearby, that’s the best type!! Get the oldest stuff. You can plow it into the garden several weeks before planting and water it a few times to wash out salts. Then go back for more and start a compost pile. That’s the best stuff.