Myself, I would be a bit leery about using end grain in a cutting board. Maybe I am way off base here, , but I would think an unsealed end grain cutting board would soak up the blood and fluids from uncooked meats.
The old, old mills around here in good ol New England used to have a lot of end grain floors. They would take 12 x 12 inch beams and cut them into 4 inch lengths. These end brain blocks would be laid out on the floor like a brick patio because when the machinery spilled oil and whatnot, the end grain wood would soak it right up. This not only prevented slips and falls, but also acted as a preservative. Over time those end grain floors would be a modern day equivalent of creosoted ties. Oil soaked to the core, they would certainly resist rot.
Now this is the reason I would be leery of using end grain cutting boards...at least ones not sealed with some kind of finish.
I have no intention of traveling from birth to the grave in a manicured and well preserved body; but rather I will skid in sideways, totally beat up, completely worn out, utterly exhausted and jump off my tractor and loudly yell, "Wow, this is what it took to feed a nation!"