Probably by a British author, because it concerns a group of people who is abducted in the United Kingdom (the narrator is abducted in London). The main theme is the identification of what was the motive for this special group of people to be selected. This motive is that all of them are related to the meat industry/consumption.
In the case of the main character, it's his conscience that we kill animals to provide food to human beings. At the end, the group is left on a planet. Their colony is found some time after, and the main genetical traits are redheadness and slanted eyes. The story was published either by F&SF or IASFM, because I read it in one of them, in the 80s or 90s, in their respective Brazilian editions.