LotR1-FotR-Seq06

[Boromir88]

I think it's the case that Tolkien does not show HOW they are 'born'. So it is not 'different' - just showing something that Tolkien glosses over?

Actually I think Tolkien makes it pretty clear that Orcs were bred like every other race...

For the Orcs had life and multplied after the manner of the Children of Iluvatar...~The Silmarillion-The Coming of the Elves.

In a letter to Mrs. Munby Tolkien states:

There must have been orc-women. But in stories that seldom see the Orcs except as soldiers of armies in the service of evil lords we naturally would not learn much about their lives. Not much was known.~dated 21 March 1963

So, I think it's pretty clear that Tolkien wanted orcs to reproduce like Elves and Men. Though, I have no strong objection to showing Orcs coming out of mudpits. Just saying it's not how Tolkien envisioned orcs as multiplying.