A livestock management system is provided that spray marks animals for sorting or market weight selection. The system includes a pen area partitioned into a feeding area containing at least one feeder and a common watering area containing at least one waterer. A walk-through scale has an inlet open to the watering area and an outlet open to the feeding area. The walk-through scale has a weighing device that determines if the animal is within the specified set weight for marking. The weighing device determines the weight of the animal as the animal center of mass crosses the center of the weighing platform. The system allows spray marking of the animal to be done in a stress free environment that improves overall growth potential.
