Some of the kill pens do some filtering, selecting out horses less suitable for random public sales, to go straight to Mexico.
We call them auctions, tradition I guess, but at this point the kill pens are mostly just marketing straight to the public, like a catalog.
The unsold ones are likely to end up in the true auction pen in nearby auctions, or straight to the trip to Mexico.
Mike McBarron (Kaufman kill pen) has described his selection process. Some horses go directly to the slaughter trucks and are not marketed. He is one that bulk supplies slaughter shippers, on addition to marketing some horses.
As far as I know, Bowie does not supply shippers. But horses may go from Bowie elsewhere to a slaughter shipper.
McBarron once described a pasture clean out load from a purported breeder. There were about 10 horses, three years old and up, had never been handled by a human, had never left their pasture. You can imagine the horse’s terror and frantic behavior. It was very difficult to get them through the basic process of intake and prep to ship.
McBarron told the interviewer that he did not market them, but put them on the next slaughter truck out, as he thought they would be as dangerous for random buyers with stars in their eyes, as they were for his own staff.
I can’t say he was wrong. But those horses were in the situation that humans had made for them. Because of a totally irresponsible ‘breeder’, they never had a chance.
I am so glad Nosey was not quite one of those. Nosey got the safe landing she deserves, yay for @2bayboys. 
She looks so happy and comfy. Please keep the Nosey posts coming 2bayboys! Makes my heart sing!
