We used just goat manure for 25 years, mixed with their oat straw bedding. It was usually a year old. Our barn has a concrete floor with a drain so when the pen was cleaned out it had some urine. We started our garden on a sand bed and one load of top soil. That manure built it up. It is like black cake flour with terrific drainage. Seriously, makes me want to bake a cake. I miss not having the manure. But not livestock. We use our compost pile now and Chicken Soup for the Soil. Its terrific.
Goat Lady from a homesteading forum, that was the best until leftists invaded, once said, my goats and chickens give me all the soil I need. Good soil is what she meant obviously because she grew pretty much everything she needed. We had loose plans for me and the family to go visit her at some point. She needed some things fixed and was going to show/teach me her system. Never did get it arranged before the forum melted down and didn’t have each other’s contact info outside of forum PMs.