Chang Hong-jen cites Sweden as an example. Swedish law stipulates that a truck bringing pigs to the slaughterhouse cannot bring more than a certain number of pigs, because research has shown that if the truck is over packed, the pigs 'brains will release an enzyme which makes them nervous and unhappy.
衛生署技監張鴻仁舉瑞典為例，瑞典法令規定一輛卡車運送豬到屠宰場，不得超過一定數量，因為有科學根據證實，若過於擁擠，豬的腦部會分泌出一種物質，造成緊張、不愉快。