Genetic testing has revealed two pandas selected for a \"breeding loan\" to a Canadian zoo are actually both female, zoo officials said. Testing in a Chinese lab revealed a giant panda intended to be sent to the Toronto Zoo with a female panda on a \"breeding and conservation loan\" was a female as well, the National Post reported Friday. \"We were all surprised but we were very relieved that it was found out before they were both transferred to Canada,\" Cynthia Shipley, the zoo\'s public relations and events manager, said. It is difficult to determine the sex of pandas, especially when they are young, experts said, because only clear feature that separates the males from females is size, with males tending to be slightly larger. \"With younger giant pandas it is more difficult to determine the sex and this is confirmed through genetic testing techniques,\" William Rapley, the zoo\'s executive director of conservation, education and wildlife, said. The Chinese government will replace the misidentified bear with a male panda from the Chengdu Zoo that is both \"healthy and age-appropriate,\" Toronto Zoo officials said. \"We\'re moving forward on a breeding and conservation loan, so in order to breed, one needs to have a male and a female,\" a laughing Shipley said. \"In that sense that would have been frustrating so we\'re really appreciative that the Chinese government went forth and [corrected] this.\"