Where does the reading こっとい (=特牛) come from?

The reading of こっとい is the result of the person who submitted the ideograph to UAX #45 making a personal enquiry to the Kyotango City Hall tax department (京丹後市役所税務課) by telephone on 2021-07-13. While there are no published literature sources that confirm this reading, the Kyotango City Hall responded that the reading of the place name 歩⿰牛化 is ほごっとい. Therefore, the reading of ⿰牛化 is likely to be こっとい.