ACTON, Calif. – One star of Steven Spielberg’s latest epic likes to end his work day by rolling around in the dirt, kicking his legs in the air and flaring his nostrils.

Finder, a 12-year-old thoroughbred, is among more than 150 equine performers featured in the Oscar-nominated “War Horse” and one of 14 who play the scene-stealing Joey. He lives on a ranch about 45 miles northeast of Hollywood with veteran horse trainer Bobby Lovgren, who oversaw all the equine action on “War Horse.”

“Plowing, riding, chasing – you name it, it’s in there,” said Lovgren, who calls “War Horse” “the biggest horse movie ever made.” Lovgren is the protégé of legendary Hollywood horseman Glenn Randall, who trained Roy Rogers’ Trigger.

Thanks to the enduring appeal of horses on screen, Lovgren, Finder and “War Horse” continue a longtime tradition of Hollywood horses that began with the earliest motion pictures.

“Bobby and his team literally performed miracles with the horses on this film,” Spielberg said. “I wanted it to feel like the horses were performing their parts as much as (actors) Emily Watson or Peter Mullan, and that is what happened. There were times during production when the horses reacted in ways I had never imagined a horse could react. You just sit back and thank your lucky stars that these horses are so cognizant that they are able to give everything to a moment.”

Those moments took months of training and a 22-member team of trainers, handlers and yes, equine makeup artists.

Set in England during World War I, “War Horse” centers on the enduring relationship between Joey and the farm boy who trained him. When Joey is sold to soldiers heading into battle, the horse begins a journey that brings him through various fighting factions and into the lives of soldiers and civilians who are moved by his strength and spirit.

The film has been nominated for six Academy Awards, including cinematography and best picture.

As the film’s “horse master,” Lovgren oversaw everything horse-related. His team prepared the equine actors for their various duties. Some became expert jumpers, others learned to stumble or feign a struggle. There were horses for riding and horses for pulling, and even stand-ins for the star horses while shots were being set. Lovgren’s team was also responsible for teaching the actors how to ride and handle the animals.

“We all became incredibly attached to the horses,” cast member Patrick Kennedy said. “Getting to know these horses and learning to ride them was the greatest privilege I’ve ever had.”

Lovgren, whose many credits include last summer’s “Cowboys & Aliens,” typically spends about three months preparing his equine actors for a film shoot. He specializes in “liberty” work, meaning the horses are not restrained in any way and learn to respond to hand signals and body language.

The 46-year-old horseman grew up in an equestrian family in South Africa that runs a large jumping and dressage barn. Lovgren said he didn’t much enjoy the public dealings that work required, so he headed to Hollywood to learn a new type of horse training. The 23 years he’s spent working in movies prepared him for the challenges of “War Horse.”

“All the scenes that we had to do had really all been done before in other films that I’d worked on, but never all in one. This took everything and put everything in one basket,” he said. “I’m very proud of my other films, like ‘Zorro’ and ‘Seabiscuit,’ but it just has a little bit in there. The horse isn’t the focal point. But in ‘War Horse’ it is, and it’s all the time.”

Lovgren met Finder while working on “Seabiscuit” and loved him so much that he bought him.

Almost everything in “War Horse” was shot with real horses, except for a few scenes that would have caused injury to the animals. Lovgren praised Spielberg’s team for their respectful approach to the horses.

Watching Lovgren with Finder, it’s easy to see the mutual love and respect between the two. Lovgren raises his arm and the powerful animal rears up. He makes a backward motion with a whip and the horse backs up. He strikes the whip on the ground and Finder bangs his hoof into the dirt. Lovgren throws a piece of wood two dozen yards away, and Finder runs to it and stands on his mark.

Lovgren doesn’t train with treats, because “if you go on set and someone walks by with an apple, what’s he going to do then?”

Instead, the animal’s reward is “I leave him alone,” Lovgren said. Still, Finder stands confidently by his side.

So with all the challenges of “War Horse,” is it harder working with four-legged performers or two-legged Hollywood types?

“I’m not going to answer that!” Lovgren said with a smile. “We all know that answer, but I’m not going to answer that.”