A stockbreeder is a farmer whose work is raising animals — cattle, sheep, pigs, horses — and in particular breeding them, that is, choosing which animals will have young, so that the next generation is healthier, bigger, or gives more milk or better meat. The 'stock' here has nothing to do with money or shops. It is an old farming word: livestock, the animals kept on a farm. So a stockbreeder is not simply someone who keeps animals; the breeding part matters. An ordinary farmer might just feed cows and sell the milk. A stockbreeder thinks about which bull to put with which cow, keeps records of the bloodlines, and often sells the young animals to other farmers. The word is fairly formal and a bit old-fashioned — you meet it in writing, in agricultural reports, in dictionaries, in news about farming. In everyday speech people usually say 'cattle farmer', 'sheep farmer', or just 'farmer'. If you want the general modern term, 'livestock farmer' is the safer one.

畜牧業者、育種畜牧農（重點在「配種、繁殖」牲畜，不只是養）