Cattle call?

When I was a youngun (that is southern for a small child) we operated a ranch in Arkansas. Nothing too big, we ran under a hundred head of cattle, grandpa had the big ranch, he ran about 300 head so we worked over there also. So I was around cattle most of my young life. And we had something that was a "cattle call". It usually consisted of a "whoop" with something after it. My grandfather could place his hand up along the side of his face, point his face in the direction where he thought the cattle were and give a loud "whoop!" and a few minutes the cattle would come over the hill heading for the corrall.
So the other day my wife says I need to take my daughter to a casting call, so I agreed. She later told me it was a cattle call as we did not have an appointment with the casting director so it would not be a big deal. Well I kind of got excited, I haven't called cows in a long time. So I started to practice in my mind all of my cattle calls. (I did this in my mind as you don't want to stand in the front yard yelling "whoop whoop whoop", it drives down your property values) for this opportunity I just knew I was cut out for. Why they were inviting my daughter to a cattle call was beyond me, but I just knew I would blow them away with my cow calling.
So we get to the hotel and there is a pretty good line already formed. We arrived early and I was sure glad we did as when we finally made it to the room where I assumed the "calls" would be made we were numbers 341 and 342. (for the record there were over a thousand people in line when we left!!) So we get there and stand in line with all these other people. There was this one guy who kept walking through the line and he would pull people out at random and take them away to another room. I just knew that they were doing special calls in that room, although I could not hear them. "Just wait till I get back there" I thought to myself, the people on the top floor will hear my "Whoop" when my turn came.
But alas the guy never did pull me out of the line. So we made our way through the line to a point where they gave us a piece of paper to fill out which had all sorts of things on it. They wanted to know my suit size, shoe size and even my dress size and my measurements. Well I have never wore a dress so I guessed a XXL would do it and my measurements were somewhere in the neighborhood of 50-40-45. The even asked my hair color, which I promptly wrote in as "bald".
So anyway after we finished our paperwork, we got our numbers and nice lady took our mug shots, face and profile just like at the police station. She pointed us to a door and I started warming up my vocal cords for the yodel of a lifetime only to pass through the door and find myself at an exit.
My daughter later told me that they just "called" it a cattle call as you feel like cattle walking through their little lanes they set up.
I am guessing whoever came up with that phrase never worked on a ranch, for when you walked through those little lanes there was usually a butcher awaiting you at the end.
So at least there wasn't a meat cutter waiting behind door number one...
I never did get to use my call...