Scientists have created gene-edited pigs, goats and cattle to produce sperm with traits such as disease resistance and higher meat quality in what they say is a step towards genetically enhancing livestock to improve food production. The animals, created for the first time by researchers in the United States and Britain using a gene-editing tool called CRISPR-Cas9, could be used as “surrogate sires”, essentially sterile blank slates that could then be transplanted with stem cells that produce the desired sperm, the scientists said. The process could help farmers rear healthier, more productive animals using fewer resources such as feed, medicines...