Developments in the twentieth century, however, have raised in some people’s minds the question of whether the kosher method of slaughter involves more suffering than other modern methods currently in use. The problem revolves around two laws passed by the U.S. Congress: the U.S. Pure Food and Drug Act of 1906, and the Humane Slaughter Act of 1958. The 1906 law prohibited slaughtering animals on the ground in order to prevent the sanitary problems of dying animals falling into the blood of other animals. Thereafter, all slaughter in the U.S., both kosher and non-kosher, used a method called “shackling and hoisting” to lift the animals and hang them by their hind legs before slaughter. This method causes significant distress and suffering to the animals.  The 1958 law required stunning by electric shock before hoisting the animal in order to prevent that suffering. However, since most halakhic authorities would not permit stunning before shechitah, and at that point there was no other more humane alternative, the law exempted kosher slaughter from the requirement to stun before hoisting.  In 1963, the ASPCA developed a pen which would keep the animal restrained but upright for slaughter and prevent the dying animal from falling on the ground which eliminated this source of suffering, but its adoption in the kosher meat industry was slow and has been far from universal.  As of 1999, 10% of large cattle, 50% of veal calves and 100% of sheep and lamb were still being hoisted before shechitah.