By Keiller MacDuff of RNZ More than twenty animal welfare charges have been laid against four shearers after an animal rights group gathered undercover footage showing graphic abuse of sheep. The charges are part of an ongoing investigation by the Ministry for Primary Industries (MPI), and stemmed from video footage from People for the Ethical Treatment of Animals (PETA) as part of an exposé into more than 30 farms and shearing sheds. The footage showed workers standing on a sheep's neck, dragging sheep across the floor, sewing up bloody wounds without painkillers, tackling and hitting sheep with blunt objects and the bodies of dead sheep scattered around the properties, the group said. PETA Asia-Pacific President Jason Baker said the charges were historic, marking just the third time members of a shearing crew had faced animal cruelty charges - the other two instances were in Australia in 2014 and 2017. "We are elated four people are charged," Baker told RNZ. "But this is just 32 sheds.…