Nothing wrong with composted manure. I'm a city gardener without easy access and I like thinking of my garden as a closed loop - nothing leaves or gets wasted and nothing (much) comes in from the outside. I garden as much as possible just with the resources I have. Not suggesting everyone needs to do that.
Blood meal is a source of pretty much nothing but nitrogen - NPK = 12-0-0. Since it is so high in nitrogen, it can burn your plants if over applied. Feeding plants nothing but N can lead to big leafy plants at the expense of fruiting. Its release time into the soil is 1 - 4 months.
Manure is a better balanced nutrient source. Chicken manure's N-P-K ratio ranges from 3-2.5-1.5 to 6-4-3; that of steer manure is usually a little less than 1-1-1. However:
Nutrient Release Rates from Compost and Manure
Gardeners need to understand that the nutrient release from compost and manure is slow, taking years. Adding compost or manure to improve soil tilth is not the same as fertilizing.
The typical nitrogen release rates from manure is only 30 to 50% the first year (fresh manure), 15 to 25% the second year, 7 to 12% the third year, 3 to 6% the fourth year, and so on. With compost and composted manure, the release rate is even slower, 5 to 25% the first year, 3 to 12% the second year and 1 to 6% the third year.
Since the nitrogen percentage of compost and manure products is typically only 2 to 4%, the amount of actual nitrogen release to support crop growth is very small.
##For soil with 4 to 5% organic matter, the mineralization (release) of nitrogen from soil organic matter will likely be sufficient for crop growth.
##For soils with 2 to 3% organic matter, the mineralization of nitrogen from soil organic matter will not likely be sufficient for heavy feeding vegetable crops. Supplement with 0.1 pound nitrogen fertilizer per 100 square feet.
##For the typical garden soil with 1% organic matter or less, the mineralization of nitrogen for soil organic matter will be minimal. Add 0.2 pounds of nitrogen fertilizer per 100 square feet.