The youngsters in the care of St. Helena High School juniors Hannah Rahn and Samantha Aragon don’t do much but eat.

And when they aren’t eating they are chewing cud or sitting in their respective fields soaking up the Napa Valley sun, the fog or the drizzle.

Rahn and Aragon are just finishing up a months-long study for a Future Famers of America project comparing the benefits of pasture grass to commercial grains in raising sheep for market. Their subjects are a baker’s dozen of Dorset sheep who share the same sire, but different menus.

The two 16-year-old students have a no-nonsense approach to the project that got underway last summer.

They used all the resources at hand — the Internet, Rahn’s enthusiasm and Aragon’s long experience in raising show animals and judging livestock. Bolstered by their parents’ encouragement, Aragon’s savings and a loan from St. Helena High School’s Ag Boosters Enterprise Fund, the girls purchased 13 purebred lambs from Minniglen Ranch in Sonoma.

Before their livestock arrived, however, the team of two first seeded a corner pasture on the Aragon ranch with red and white clover, built a fence, divided a small barn for the new occupants and arranged for them to drink from the same water source.

Because this is a feed-lot situation, the new sheep ranchers avoided naming the animals — with one exception.

“One in the grass-fed group has a name because he’s bigger than the rest and he has personality,” Aragon said. “He’s friendly and he comes up and talks to you.”

“We have no attachment to them,” added Rahn, who learned what most sheep ranchers already know. “They aren’t exactly the most loveable animals, they don’t have the best personalities.”

Although Aragon has been raising animals since her days in 4-H, this is Rahn’s first experience with farm animals. Her ag interests lean more toward viticulture but “This is pretty cool,” Rahn said as she watched the grain-fed group munch on dried alfalfa. “It’s interesting to see the different elements and everything we’re testing for.”

Aragon and Rahn provided a short course on the flocks’ interesting digestive arrangement — sheep have four stomachs to better utilize every nutrient grasses have to offer — and a cud-chewing habit that they share with a number of mammals, cattle and goats included.

Over the course of their study they attended seminars at Chico State University, conducted weekly weighings of each sheep in the two groups, wormed the sheep as needed and took blood samples. They also surfed the Web to locate labs with the most affordable rates for testing the samples for cholesterol and fatty acid levels.

“We’ve put a lot of time and money into this project,” Aragon said. “Just to get it off the ground cost $1,500 for the purchase of the sheep. Our omega-3 tests were $600 and the cholesterol tests were $200.”

Hope to sell lambs

The teen researchers are hoping to recoup some of their expenditures through the sale of the animals — six are already spoken for — but the rest need to be sold by March 21 before they are turned into chops. Afterwards the researchers will conduct post-slaughter carcass evaluations of the ribeye areas and the kidney, pelvic and heart fat, and use the data to assign yield and grade designations to the meat.

Rahn and Aragon’s findings to date appear to show that their grass-fed sheep are heavier and have higher levels of the benefical omega-3 fatty acids. But they also show higher levels of cholesterol, “so it’s a tossup,” Aragon said. “It all depends on what a particular person needs for their heart health.”

As March sweeps along, the pair are up against a time crunch to get the data compiled and their report finished in time for the state FFA competition in Fresno. Even so, they won’t stint, Rahn said. “We want to win.”

The two are spurred by their project’s third-place finish at an FFA competition at UC Davis earlier this month — despite the lack of completed data — and dream of placing first at the state level. The win would take them to Indianapolis and the national convention in October.

Meanwhile, Rahn and Aragon spent a recent weekend trying to condense their study’s introduction to 12 pages — and laughed as they mused about whether to reduce the font size or narrow the margins in order to meet the requirements.

However they manage it, it will be a scramble. The results of their final evaluations won’t be available until the day before their report is due. But both have entered agriscience projects before and know the ropes.

Rahn’s research on straw mulch and the germination rate of winter cover earned a first at the state level last year. Two years ago Aragon made a study of the effects of selenium on birthing ewes and goats.

Even after the report is submitted, Aragon and Rahn won’t be finished.

 Come summer they are planning a lamb barbecue for all those who supported their project and they’ll hold taste tests to determine whether grass-fed or grain-fed lambs are the tastiest.

 As they near the end of data collection, Rahn and Aragon said the research has been interesting but complicated and time consuming. “I’ve lived on a farm my entire life and I’ve been showing animals since I was 8,” Aragon said, “but I didn’t realize this project was going to be so much work.”

 (To learn more about purchasing a lamb call 965-1413.)