Recent research for the Ministry of Agriculture Fisheries and Food (MAFF) has shown that use of the captive-bolt stun gun on animals infected with BSE can transmit the infected tissue into parts of an animal used in the human food chain. This presents a risk to humans of contracting nvCJD because the same unsterilized captive bolt is used on successive animals. Infected tissue was also detected on the hands of operatives and on slaughter equipment. In the USA similar research (known as the Harvard Study) by the Department of Agriculture (USDA) concluded that stunning methods using penetrative bolts carry a great risk to human health since this can transmit the BSE agent. US Food Safety and Inspection Service (FSIS) has amended the Federal meat inspection regulations to prohibit the use of these types of penetrative captive bolt stunning devices. Shechita avoids these hazards since the brain is not damaged and so it protects human health, as well as animal welfare.