Down on the Farm
As OSU’s mobile veterinary clinic travels from farm to farm in Benton County, small-talk is all about large animals and their care. Professor Charles Estill, resident vet Bronwyn Crane, and fourth-year students Jaime Ueda and Dana Hoyt trade stories of midnight emergencies during on-call rotations — of a difficult birth that ended in euthanasia, of a horse struck by a car in the fog.
Jaime Ueda braces herself against the 1,500-pound tranquillized cow as it shifts nervously from side to side. She hesitates, looking from the cantaloupe-sized swelling on the Holstein’s chest to the seven-inch knife she grips in her hand. “Are you kidding?” says the 4-foot-11, 100-pound veterinary student. “Ohmygod.” And then, taking a deep breath, she drives the knife into the abscess, sending a spray of white fluid across the hospital pen at the Van Beek Dairy.
“You did it!” Professor Charles Estill says, proudly. “You didn’t wimp out!”
Lancing abscesses is just one of the practical skills Estill passes on to the fourth-year students enrolled in Rural Veterinary Practice I, a required course in OSU’s College of Veterinary Medicine. Even students planning to practice on canaries or ferrets need experience working on farm animals, Estill says. That’s because biological agents such as anthrax and plague, and infectious diseases like avian flu and hog cholera, originate among livestock. A bioterrorist attack or a deadly pandemic would require veterinarians to step into the breach — to be, in Estill’s words, the “first line of defense.” In such a crisis, even a suburban cat-and-dog doctor could be recruited to work with infected herds or flocks. “Their license qualifies them to work on all species — every living, breathing thing on this planet, except people,” notes the 55-year-old specialist in bovine reproduction.
So on this chilly November morning Ueda, who aspires to a clean, white-coated career with lab animals, finds herself traveling the back roads of Benton County clad in canvas coveralls and rubber Muck boots. Unmindful of the passing landscape — of the leafless oaks etched in fog and the frost lingering beside the road — the 25-year-old from Oahu and fellow student Dana Hoyt, a 34-year-old Oregonian from Klamath Falls, chat about trans-tracheal washes and sheep scald, primary uterine inertia and dystocia as they ride along with Estill and resident vet Bronwyn Crane, 27, a native of Canada’s Prince Edward Island.
The “farm-visit” program, launched in 1981, serves a dozen commercial farms and hundreds of what Estill terms “backyard pets and hobby animals” such as llamas, alpacas, pigs and goats within a 30-mile radius of Corvallis. He and his students do pregnancy checks, disease surveillance and routine vaccinations for dairy cows, beef cattle and horses on a weekly or monthly basis. With referrals from local vets, they also handle emergencies and difficult cases throughout Oregon and, occasionally, in Washington and Northern California. The farm-visit teams conduct research, too, collecting specimens for studies on nutrition, reproduction and disease among the herds.
Today, their Ford F350XL mobile clinic — stocked with antibiotics and diagnostic compounds, syringes, blood-collection tubes capped in a rainbow of colors, portable ultrasound and X-ray machines, and boxes and boxes of latex gloves — stops first at the OSU Research Dairy. Over the past four decades, scientific breeding of dairy cows through genetic selection at OSU has doubled annual per-cow milk production, from 10,000 pounds in the 1960s to 20,000 pounds today. A healthy animal can pump out 100 pounds of milk every 24 hours.
In an industry that depends on slim profit margins for economic viability, any drop-off causes concern. So when one of OSU’s research cows suddenly started coming up short at milking time, Estill got a phone call.
The university’s high-tech milking barn hums with the rhythmic swish-swish of vacuum pumps as a New Zealander nicknamed “Kiwi” works a row of plump udders with practiced efficiency. The milk is measured as it streams through a jumble of transparent tubes, the quantity recorded instantly on electronic panels. The glowing numbers confirm the problem: The recalcitrant cow has given only 21.5 pounds so far that day — less than half that of her barn mates.
“Her name is No. 710,” Estill tells the students as he leads them to the “loafing barn” with the just-milked cow in tow. “OK, ladies, check her out. There’s room for lots of stethoscopes.”
The three women press their stainless-steel instruments against the Holstein’s white-and-black hide. Lifting her tail, they insert their digital thermometer and draw blood from her “tail vein.” After getting normal readings on heartbeat and body temperature, they perform “simultaneous percussion and auscultation” (thumping and listening) and “palpation” (feeling around inside the reproductive and intestinal tracts). No hint of disease. Tests for udder infection and ketosis again turn up nothing. Cow No. 710, they decide, is suffering from indigestion (no small problem for an animal that processes 50 pounds of feed a day).
“Lots of gas,” Crane concludes. Back at the lab, the blood sample shows low magnesium — a common finding associated with bowel trouble in cows. The Rx? Oral Epsom salts.
Not every vet-med mystery is so easily solved. Sometimes it takes extensive lab tests or even a full-blown study. In the winter of 2003-2004, many Willamette Valley dairies saw a decline in birth rates among their herds. After analyzing the animals’ feed — a mix that typically includes alfalfa, corn, grasses such as fescue and ryegrass, cottonseed and soybean meal, beet pulp, barley, canola and a “mineral pack” — Estill and fellow OSU researchers discovered an unknown compound, which they traced to mold. They’re now searching for ways to prevent harmful mold growth through silage inoculants, as well as proper harvesting and storage of hay and silage.
With support from the Agriculture Funding Consortium, Estill and a team of Canadian researchers are also investigating the effects on dairy-herd fertility of omega-3 fatty acids in flaxseed. He conducts field tests at the Van Beek Dairy in the hamlet of Bellfountain, where the mobile clinic travels every Monday. Today, the farm’s 1,350-head herd has Estill, Ueda, Hoyt and Crane up to their armpits in work. After vaccinating five-month-old calves for brucellosis, and then tagging and tattooing the animals’ ears to meet federal regulations, they each slip a shoulder-length Ag-Tek Poly-Sleeve onto their arm. Working methodically from barn to barn, they take turns reaching deep inside dozens of pregnant (or possibly pregnant) cows to gauge the growth of the fetuses. Standing on her toes, Ueda leans in and then calls out: “Oh! This is very cool! I can feel the tip of the fetus.” Estill tells her that sometimes, the unborn calf will suck on the examining vet’s finger.
At the end of the day, as they head for the muck hose and the warm truck, the team pauses beside a heifer in labor. Two tiny hooves have emerged, portending a new member of the Van Beek herd. When Estill talks about this part of his profession, he sheds some of the clinical matter-of-factness he typically exhibits. “Who could walk by an animal giving birth and not stop to watch?” he asks. “Who wouldn’t be awed by the wonder of the whole process?”