Define "Liquid."

I see many strange things around here. This one kinda defies my logic. Saw this on the interstate on Wednesday the 28th between Menifee and Plumerville westbound on I-40.


At first I wasn't sure what it said, perhaps it was something cute, I don't know. But as I drew closer, the message became clearer.





I know it may be hard to see on the chrome, so I'll enhance it.






I think the funniest part is the tag line under "Hauling Liquid Chicken."

My guess is that it's chicken scat, but who knows? I can't imagine that it's liquefied chicken -- wouldn't that still be edible?

And for the record, by Googling "Haulin' Liquid Chicken," I can see that I'm not the only one dumbfounded in the search for a meaning to this phrase.