One of the challenges of raising livestock for food in Hawaii is our isolation: Surrounded by water and far from the continental U.S., shipping in feed for those animals is a formidable expense.

But innovative minds at the University of Hawaii’s College of Tropical Agriculture and Human Resources have been working on ways to utilize Hawaii’s resources for supplemental feed to make livestock farming more financially viable. Rajesh Jha, an associate professor in animal nutrition, and his students have developed award-winning research on feed for chicken and tilapia.

Their work on chicken feed zeroes in on local byproducts of cassava, fish and macadamia nuts. One trial underway focuses on cassava root, turned into chips and then ground, as a supplement for imported corn fed to chickens as an energy source. Cassava could replace as much as 37.5 percent of corn for maximum cost savings, according to Waialua chicken farmer Julius Ludovico of J. Ludovico Farm, who has been conducting the first trial of the feeds on his farm. Another centered on fish bones, ground into meal to provide protein. Because of its saltiness, he said, fish meal can replace only small amounts of imported soy meal, about 2 percent. More than that, and the feed was unpalatable for chickens.

But a highly successful supplemental feed tested by the farmer is macadamia nut “cake,” the byproduct of nuts pressed for oil, which can replace about 15 percent of soy meal. Not only does the cake lower feed costs by 20 to 30 percent, it contributes to producing an exceptional-tasting bird. And for a farmer, that means a premium product that can be sold at a premium price.

Ludovico, a former hog farmer, began pasture-raising chickens in 2013. Ludovico’s meticulous farming method and quality control delivers isle birds prized for their quality, especially among chefs of the 10 or so local restaurants he supplies. The farmer also sells a limited number of whole chickens to the public on Wednesdays at the Blaisdell farmers market. (See farmers market listing on Page 16.)

“I’ve been approached by distributors, but I don’t know how the markets would treat my product,” he said of his choice to sell direct to customers. “I deliver my chickens on the day of slaughter.”

Chef Mark “Gooch” Noguchi of the Pili Group appreciates Ludovico’s dedication nearly as much as he does the farmer’s product.

“To start, local chicken is hard to get. It’s expensive to raise and it’s expensive for chefs. Julius has worked really hard on his system to sell his chicken at the most reasonable price possible,” Noguchi said. “I talk to Julius a lot, and he says, ‘Hey, I’m trying this or that out. Let me know what you think.’ He thinks about chicken like a chef thinks about food — he’s always trying to make it better.

“Most of all, his chicken tastes good.”

Ludovico’s birds live in movable “tractors,” cage structures with tentlike roofs that protect the animals from predators and the elements while allowing them to feed on fresh grass, along with the soy and corn feed.

“I move the tractors daily so that the chickens can be on fresh grass,” he said. “They eat the grass as supplemental feed, and I don’t want them sitting on manure. After a day, I personally think it affects the product quality — it’s just cleaner.”

Each 5-1/2-square-foot tractor holds 25 to 30 chickens. Ludovico maintains 64 tractors that he moves across leased farmland.

He said different grasses affect the taste of the meat. Chicken that consume California grass, for instance, are gamier than those raised on fields of black oats. “The meat is sweet,” he said. His top grass: perennial peanut — “It’s best for sweetness and protein content.”

The addition of the mac-nut cake further enhanced the quality of Ludovico’s birds.

“With the mac-nut cake, the birds grew to size nicely and the organs were better. The livers were cleaner, the gizzards were bigger, the intestines were cleaner, and the taste was phenomenal,” he said.

Then there is economics.

“When you raise pasture chickens, they eat grass but the bulk of their diet is grain. The No. 1 factor is feed cost,” he said. “Twenty to 30 percent savings is huge. Farmers generally make a 4-percent profit, so even at 10 percent, that’s a huge savings to the bottom line.”

Ludovico has since completed the trial and said he isn’t currently using mac-nut cake, but he has picked up a few techniques from the research to maintain the high quality of his birds.

Jha is hoping to get more funding so he can expand the trials. The value for such research, he said, is multifaceted.

The supplemental feeds are “sustainable economically, environmentally and contribute to food and nutrition security,” he said. “And when you reduce imports, you reduce the environmental footprint. These byproducts are not going to the landfill. They promote industries of these items and create a market.”