American military researchers are reported to have blown up live pigs dressed in body armour in an attempt to study the link between roadside bomb blasts and brain injury.
The research determined that body armour does not worsen brain injury, reports The Telegraph.
Researchers strapped pigs and rats into Humvee simulators and subjected them to about 200 blasts, according to Pentagon documents and interviews obtained by USA Today.
The tests were carried out over an 11-month period.
The explosions ranged in intensity, wounding some of the pigs and killing others.
Jan Walker, a spokesman for the Defense Advanced Research Projects Agency (DARPA), which conducted the study, told the paper that roadside bombs are the top killer of US troops in Iraq and Afghanistan.
The research also showed that body armour protected troops' lungs and was critical to surviving blasts.
Pigs that were not dressed in body armour died from blasts within 24 to 48 hours, while those with armour survived "significantly higher blasts," Walker said.
However, animal rights campaigners have condemned the tests.
Martin Stephens, vice president for animal research issues at the Humane Society of the United States, told the paper that blowing up pigs raised "red flags,".
Colonel Geoffrey Ling, who led the study, said pigs were good subjects because their brains are more similar to human brains than those of rats. Pig hearts and lungs are also similar to humans'.
The Pentagon said a minimal number of animals were used in the testing and that they were treated humanely at all times.