Wagyu cattle breeders at Washington State University reached a milestone this summer, confirming their first homozygous polled heifer — a young cow that has inherited genes from both parents that prevent her from growing horns.
For animal safety reasons, cattle raisers typically de-horn bovines manually, a process that’s expensive for the farmer and uncomfortable for the calf. By inheriting hornless genes from her sire and dam, the purebred heifer named WSU Miss L120 will pass on the trait to all offspring.
“She’s a great addition to our herd,” said Bailey Graham, assistant manager at the WSU Beef Operations Center. “She brings a great trait that can really help with animal care and welfare.”
Scientists in WSU’s Department of Animal Sciences have studied and bred Wagyu cattle, renowned for exceptional beef marbling and tenderness, for more than 30 years. Efforts to breed a homozygous polled animal began in 2018, and DNA analysis by the American Wagyu Association confirmed the success earlier this summer.
To get a homozygous animal, scientists first bred heterozygous cattle — bulls and cows that inherited hornless genes from one parent. Genes for hornlessness are dominant. If an animal inherits the gene from one parent, it will be hornless, but may pass on genes that turn on horns to offspring. With a homozygous polled animal, the hornless genes are locked in: no offspring will grow horns.
In the wild or out on the range, horns are a useful defense. But in close quarters, horns can be problematic. Horned cattle can get caught on pens and rails, and may accidentally injure themselves, other animals, or their handlers. Life without horns is easier and safer.
The WSU team credited WSU professor emeritus and Bar R Cattle Company owner Jerry Reeves for his support of the breeding program. One of the first ranchers to raise Wagyu cattle in the U.S., Reeves helped start WSU’s Wagyu herd in the 1990s. For more than a decade, he has donated bull semen with desired genetics to improve the WSU herd.
In close quarters, horns can be problematic — horned cattle can get caught on pens and rails, and may accidentally injure themselves, other animals, or their handlers.
Miss L120’s sire, Reeves’ own Bar R G4 ET, is a top-rated U.S. bull for marbling. Her mother cow also had great performance traits, and odds are good that L120 will have offspring with very well-marbled beef, an important goal in Wagyu breeding.
Handlers have also noticed her gentle demeanor; she is the granddaughter of one of the gentlest cows known in the WSU herd. Docile and calm, Miss L120 is predicted to become a great mother to future calves.
“We expect her to thrive and become a mainstay in the WSU herd for years to come,” said Brent McCann, former Beef Center operations manager, who led the breeding project.
Animal scientists are always working to improve the WSU cattle herd, which includes 40 Wagyu animals and more than 100 Angus and Angus-Hereford crosses.
“A major concept is breeding animals that fit our resources,” said McCann.
That means seeking smaller, sounder animals that are thriftier to feed, easy to handle, and have good maternal qualities.
Breeding better livestock aids the beef program in its mission of teaching, research, and service to producers. The Beef Center is a testing ground for animal science research, and WSU students are involved in all aspects of breeding and care, from feeding and cleaning to performing vaccinations and tracking animal health and condition.
The heifer’s name is really a designation: WSU is her ranch, the letter L indicates she was born in 2023, and 120 means she was the 120th beef calf born that year.
Miss L120 is officially the first of several similar animals in the WSU herd. Genetic testing is expected to confirm additional heifers born in 2023 and 2024 that carry the homozygous polled genes. These strides help keep WSU in step with the broader cattle-raising industry. “It’s a good accomplishment,” Reeves said. “There aren’t many homozygous polled Wagyu around. They’re hard to find.”
