veterinarians and students examine cow
Dr. Bret McNabb, center, shows residents and students how to quickly assess the health of a cow's eye.

Watch UC Davis livestock veterinarians and students in action at the Eden Valley Ranch. Watch Now

by Rob Warren, UC Davis VMTH Communications & Marketing Officer

Tucked into a picturesque mountain range 175 northwest of campus sits the Eden Valley Ranch, where a menagerie of animals benefit from visits by UC Davis veterinarians and students. The Livestock Herd Health and Reproduction Service (LHHR) recently made its annual trek to the ranch, much to the delight of everyone involved. The ranch houses 190 cattle, eight buffalo, five sheep, three horses, two llamas, one camel, and a McNab collie named Ring. Hundreds of wild animals—including yaks, deer, bears, mountain lions, and elk—inhabit the surrounding mountains, and are not afraid to wander into the ranch.

Leaving Davis in the late afternoon, the group of two veterinarians and four students arrived at the ranch just in time for a dinner cookout. After an evening of storytelling with the nearly dozen ranch hands and caretakers, the group retired to the bunkhouse in anticipation of a sunrise wake-up call. The focus of this most recent visit was to perform pregnancy checks on 94 head of cattle.

Having rounded up most of the herd the night before, the cowboys drove the cattle into the pen early the next morning as the group was waking. After a quick breakfast, the team got started.

The cows were led into a chute for each to receive an individual examination. Capturing a cow in a chute is a skilled craft, and Miguel Chappell, cattle manager of the Eden Valley Ranch, is an expert after years of this. He times the closing of the chute precisely as the cow’s head is out the front of it but before her legs and torso have a chance to escape. Leading cattle into a chute can be a dangerous activity, but it is clear that safety is the #1 priority on this ranch. A cow was never released from the chute until everyone in the area knew she was coming out. As some may not want to go directly back into the pen, the cowboys were ready to jump in at a moment’s notice. At one point, Chappell was up on a nearby horse in a spilt second to guide a stray cow not cooperating out of the chute.

The most efficient way to diagnose a pregnancy is to perform a manual palpation. Since the uterine wall sits against the rectum, the test is done transrectally, where the clinicians and students feel for certain indicators of a pregnancy. If a pregnancy is in an advanced stage, the easiest thing to palpate is the fetus itself. However, early pregnancies are determined by palpating fremitus (vibration of the uterine artery), which grows as the fetus ages. Another indicator is the placentome, which is where the fetal blood supply is attached. Using a combination of these techniques, pregnancy can be confirmed and accurately staged within about two weeks, starting after 30 days.

The students took turns performing their examinations. First up was Ethan McEnroe, a fourth-year student from Bakersfield. McEnroe palpated about 25 cows while Maria Vezza, a Ross University fourth-year student from Long Island (Ross University, located on the Caribbean island of Saint Kitts, does not have a teaching hospital so their students complete their clinical year of study at other veterinary schools) and her sister Christina, a second-year veterinary student at Auburn University (interning at UC Davis for the summer), administered vaccinations to the cattle. Each cow was vaccinated for respiratory and reproductive viruses, bacterial reproductive diseases, and clostridial diseases.

Keeping an accurate account of the proceedings was Sarah Tirrell, a fourth-year student from Akron, Ohio. Both ranch hands and students kept a detailed spreadsheet of every cow’s examination, including details of the pregnancy and what drugs were administered.

The four students rotated their roles throughout the morning so each had a chance to perform examinations. Dr. Bret McNabb, chief of LHHR, and resident Dr. Muzafar Makhdoomi conferred with each student about their findings and confirmed with their own examinations. The group efficiently finished the entire herd in under four hours.

Any cows that were “open,” or not pregnant, received an orange mark on their back and the hair of their tail was trimmed so the ranchers can easily identify them later when it’s time for another round of breeding.

Throughout the examinations, Drs. McNabb and Makhdoomi continually asked the students questions about different aspects of herd health. Nearly every minute of interaction with the students was used as a teaching opportunity. The students were inquisitive and eager to learn as much as they could on the trip. This ranch visit presented a wonderful hands-on opportunity for students to gain real-life experience working with livestock.

Dr. McNabb also used the time to discuss best practices with the ranchers.

“It’s a great learning opportunity for us when the UC Davis vets and students come out,” said Chappell. “Any questions we have – they explain everything to us, and are always available whenever I call.”

Beyond the pregnancy checks, the group also examined a bull with an eye injury and a cow with a mass on her lower jaw. Dr. McNabb questioned each of the students on what may have caused the injury and what the best treatment options were. These unexpected parts of examinations that seem to pop up at most field visits keep the veterinarians and students on their toes.

“You can’t teach that in a classroom,” jokingly exclaimed one of the ranch hands, who seemed to all enjoy their interactions with the students.

In addition, the students examined the overall health of the herd, noticing the flesh tone, body position, and coat appearance. Also checked were their feet, legs, and eyes. As each cow exited the chute, its gait was analyzed for lameness issues. Based on all of these observations, the herd was deemed in good health, and displayed no signs of systemic illness. The cows’ health is a direct indication of how these ranchers genuinely love what they do and seem to not want to do anything else, no matter how much they may be enticed.

#   #   #