The barbecue season has just gone past its peak on the 4th of July. Joyous vibes ooze into a backyard filled with the aroma of a juicy ribeye cooking over charcoal. While barbecue and cookouts have been a custom ingrained in American culture for over 200 years, the hunt for a better cut of meat never stops. Beefalo comes in clutch— a bison-cattle crossbreed with
higher-protein meat that’s more tender than conventional beef, as more and more Americans turn toward healthier options. However, one of the major selling points of the Beefalo breed, its bison lineage, seems a bit shaky as genome analysis of the breed’s earliest animals shows barely any bison DNA.
Beth Shapiro, an evolutionary biologist at the University of California, Santa Cruz, finds it quite surprising that most Beefalo individuals show no detectable bison ancestry. She and her colleagues study the genomes of species that can produce hybrids, such as bison and cattle. In the first genome-wide analysis of the breed, her team examined preserved semen samples, primarily collected from 47 animals in the original Beefalo herd of the 1970s and ’80s. Her research objective is to study whether the bison ancestry has waned in the 50 years since they were first bred.
And the bison genes did get lost in time.
Stats, Stance, and Steak
Out of the 47 samples, 39 of the animals contained no bison ancestry, and the eight Beefalo with any bison DNA didn’t meet the breed standard of being 37.5% American bison, as defined by the American Beefalo Association (ABA). However, they take a different stance and do not endorse the results. The association’s president, Dan Stricker, says that all “full-blood” Beefalo in their registry must pass DNA tests through labs at the University of California, Davis, and at Neogen Genomics in Edmonton, Alberta, before their bison ancestry is confirmed.
“We have serious concerns that the samples used in Dr. Shapiro’s study do not accurately represent modern, registered Beefalo that have been selectively bred for bison traits over many generations,” Stricker says.
The researchers acknowledge that they sampled only a few present-day Beefalo, while focusing most of their attention on the breed’s founding individuals. Study coauthor Jonas Oppenheimer, an evolutionary biologist now at the Center for Paleogenetics in Stockholm, doesn’t see this as a possible point of dispute, since it is unlikely that present-day individuals contain more bison genes than the founders.
Bison-Cattle Crossbreeding is Tough
The lack of bison ancestry in these Beefalo suggests that although interbreeding is between a bison and cattle is possible, it is difficult as genetic mixing is almost absent. Throughout the 20th century, breeders tried to establish stable populations of bison-cattle hybrids, without much success.
Beefalo may contain little bison ancestry, but its the cattle genes that have definitively leaked into wild bison population. Conservationists worry that this mixed ancestry can cause behavioral shifts in bison, compromise disease resistance and legal protections. However, Shapiro and Oppenheimer’s work on cattle-bison hybrids suggest that the concerns have been blown out of proportions, since the genetic mixup has been scarce and far less consequential than previously thought.
Copyright @smorescience. All rights reserved. Do not copy, cite, publish, or distribute this content without permission.
