After Extensive Research

from http://en.wikipedia.org/wiki/Euchre_variations

"For some players in the Midwest, when a team has nine points, players place the score cards next to each other, face down. The team is now "in the barn" (also "on the corner") or "mooing". Some players have also been known to place the two score cards behind their ears upon "entering the barn." A celebration ceremony involved with "entering the barn" is "milking the cow," whereupon one member of the team that just "entered the barn" interlaces their fingers and points their thumbs downward. This completed, their teammate "milks" the down-turned thumbs just as one would milk a cow's udder. Another action that players sometimes do is known as "Churning the Butter." Players lock fist into palm and move their hands up and down as if "Churning the butter." If the team scores their tenth point then the "barn doors are opened:" the cards are flipped to show all ten pips. Actions such as this, however, are considered insulting."