Manufactured blood (or also known as: cultured blood) is actual blood.
However, it is not blood taken from a living being. It is manufactured in a factory. For the manufacturing (or growing) of the contents of the blood, stem cells from an organism are used. These are usually stimulated into dividing and produce the contents of the various types of manufactured blood.
Blood is made up of water (mostly). It contains red blood cells (RBC), hormones, peptides, oxygen and many other substances. During its flow throughout an organism, it constantly changes contents. Defining what blood is, is therefore more difficult than it may seem at first…
Like a river
In a living organism, blood can almost be seen like a river of water, flowing through the organism.
Various organs are connected to this river and may add and/or take away substances. For example, the lungs will remove CO2 and add oxygen. The blood contents before the blood enters the lungs is different from the blood contents after it leaves the lungs. The same goes for the liver, pancreas, bowels etc. etc. There are many organs changing the contents of the blood while it flows on it’s way through the organism.
Many substances in blood are kept at a certain level by various balancing-mechanisms and blood contents changes with the age of the organism too. Blood will even change contents depending on whether the animal is stressed or not or under attack from bacteria etc.
Types of manufactured blood
Manufactured blood is made with a special purpose. The blood contents is established as a function of this purpose.
For example: to grow organs, muscle or other cells, it may be useful to have some growth hormones in the blood. In nature, fetal blood will often contain these hormones.
Most blood-types will contain red blood cells, to be able to carry oxygen. Also, in manufactured meat, red blood cells contain iron which adds to the taste of the meat.
A serum is a more minimal type, with less substances in it. A plasma has even fewer added materials and is closest to plain water of the manufactured blood types.
Blood could also be manufactured for human-donor purposes. However, the supply of natural donor-blood seems enough at present and getting blood from human donors is not too difficult. The issues with testing and getting artificial blood approved for use in humans would probably be prohibitive for any commercial company.
Manufacturing blood, can it be done?
Culturing blood has already been done in a lab. See for instance this clip. Red blood cells (and other blood cells) have been created from stem cells in 2011 and repeated many times thereafter. Until now, nobody has manufactured blood cells in volume in a production environment.
Update 23/9/2018: Japan has approved a clinical trial with human cultured blood. In this trial, lab-grown blood cells will be transfused into people.