Why was Jesus born in a manger, a barn?

Why was Jesus born in a manger, a barn? Well, I dont honestly know, but all through the Old Testament, they were sacrificing animals to God for just about everything. Jesus was God's ultimate sacrifice....His own son, a part of Himself, He sacrificed for every person on Earth....so it makes sense that since all other sacrifices start that way, that Jesus's life also start the same way....Just a thought...