Bull calf gene-edited to produce more male offspring

Scientists at the University of California, Davis, have produced a bull calf, named "Cosmo", who was genome-edited as an embryo so that he would produce more male offspring. Using gene-editing tool CRISPR, scientists successfully inserted a gene called SRY, which is responsible for initiating male development, into a bovine embryo. They said 75% of his own calves will be male.