Yes. Blood is nutrient rich, since blood is what carries nutrients to every organ in the body. Here is an article about it http://science.howstuffworks.com/environmental/life/human-biology/blood.htm
One of the reasons I don't feed prey model raw is that I cannot accurately replicate whole prey...
Not all food items should be cooked in order for dogs to get the best nutrition possible.
The meat part should be left raw. This is safe for dogs and will give them maximum nutritional benefit. Vegetables and grains should always be cooked because dogs cannot digest raw plant products...