In Working Equitation Cattle Handling appears twice.
Best know is the timed event. But most horses and riders need a first experience with cattle handling in a more leaning conducive setting such as the Herding Cattle From Gate to Gate obstacle in the Ease of Handling Phase.
In the EOH Phase a small number of cattle are contained in one of two connected enclosures. Each enclosure is from 12 to 30 feet on each side.
The objective is to:
Open a gate and enter pen 1 containing cattle, closing the entry gate to secure the cattle.
Open a sifting gate connecting the two pens.
Move the cattle into pen 2. Close the sifting gate.
Exit pen 2 securing the cattle.
The following video is a very nice ride by a talented horse and rider. The Cattle Herding Obstacle occurs around 2:15 into the video, but you are encouraged to view the entire video as this is what we would all aspire to.
Courtesy Haras Dos Cavaleiros.
This activity is a great deal of fun for both the horse and the rider. When properly introduced to cattle such as in practicing this obstacle, the horse has a very interesting task to perform. Rarely does a horse object to working with the cattle, and most show a keen interest and enjoyment as their confidence builds. All breeds of horses can perform this task with equal finesse.
The Timed Cattle Handling phase
tests the ability of the horse and rider to work cattle individually and with teammates. The test is performed with a team of 3 or 4 riders. The objective is for each rider to move an assigned cow from the herd and put it in a designated pen, and for the team to demonstrate teamwork by herding/containing cattle efficiently and accurately. This is a timed event.
The recommended minimum arena is 230 ft. x 100 ft.). It must have adequate, safe fencing to contain cattle. A holding pen is set up at one end of the arena. The exact size and position of the holding pen can vary; it can either be within the perimeter of the arena or set up as a separate pen. At the opposite end of the arena is the herd zone, where the cattle are held prior to the start of the test.
A foul line separates the herd zone from the sorting zone. A chalk line or flags/cones at each side of the arena mark the boundary between the herd and sorting zones.
Rules description courtesy of the US Federation of Working Equitation Organizations