Hornless bulls are now a thing, thanks to gene editing
Hornless animals are less likely to harm other animals or dairy workers, and tend to be less aggressive.
Scientists have been successful in raising six genome-edited offspring of a dairy bull. And here’s the catch - these bulls have been genetically modified to prevent them from growing horns.
You read that right.
Reports published in the Journal of Nature Biotechnology state that the experiment has been successful, and none of the offspring have developed horns. A full blood work and physical exam of the calves have found them to be completely in good health.
Researchers also checked for any unexpected changes, by comparing the sequenced genomes of the calves and their parents. “Our study found that two calves inherited the naturally occurring hornless allele and four calves additionally inherited a fragment of bacterial DNA, known as a plasmid,” said corresponding author Alison Van Eenennaam, with the UC Davis Department of Animal Science.
Thankfully, scientists did not observe any other unintended genomic alteration in the calves.
What can be done with the additionally inherited bacterial DNA?
Van Eenennaam says that the plasmid does not harm animals. But it makes the genome-edited bull a GMO, as it contains foreign DNA from another species - the aforementioned bacterial plasmid.
Scientists say that the Plasmid integration can be addressed by screening and selection. In this case, this was done by selecting the two genome-edited hornless bulls that inherited only the naturally occurring allele.
“This type of screening is routinely done in plant breeding where genome editing frequently involves a step that includes a plasmid integration,” said Van Eenennaam.
“Our data indicates the need to screen for plasmid integration when they’re used in the editing process.”
Why do we need bulls without horns?
Horn grow naturally to dairy breeds but they are removed from the calves at a young age. The process is unpleasant and has implications for animal welfare.
Also, hornless animals are less likely to harm other animals or dairy workers, and tend to be less aggressive.
Gene editing offers a pain-free option to dealing with horns.