A black and white cow, mooing   S HOO," Hetty Thompson cried, waving her battered old felt hat at the clucking cluster of hens eddying around her legs as she plowed through the flock towards the chicken house. "Scat. You, Solomon," she called out, directing her words at the bobbing comb of the big rooster strutting at the edge of the mob. "Don't just stand there like a satisfied cowhand after a night in Reno. Get these noisy females outta my way." She batted at the hens and they scattered with a