Yes, blood is much saltier than meat. For the most part, extracellular
fluid( an example is blood plasma) has a high concentration of Na ions.
Inside the cells, K+ ions are dominant. There is a pump in the cell wall
that maintains that gradient.

So if you use blood in your cooking, as many traditional cultures do, you
get quite a bit of salt from that source alone. My grandfather farmed until
1949. When they butchered a hog, they always saved the blood to make various
sausages and sauces. Talk about rich!

Michael