The UK's only female giant panda Tian Tian has been artificially inseminated for a third time after two previous failed attempts. The procedure took place earlier today, before an attempt is made at natural mating with partner Yang Guang later, Edinburgh Zoo said. On the two previous occasions keepers have inseminated Tian Tian she has failed to produce a panda cub. Scroll down for video . Tian Tian in her enclosure: She was artificially inseminated today with an attempt at natural mating to follow . Tian Tian the panda in her enclosure at Edinburgh Zoo: On the two previous occasions keepers have inseminated her she has failed to produce a panda cub . Semen from Yang Guang was used in the procedure carried out by a team of three vets at the zoo, alongside a panda expert from China. Iain Valentine from the Royal Zoological Society of Scotland, which runs Edinburgh Zoo, said: 'Natural mating will also be attempted today before the short breeding window comes to a close this afternoon. 'Both pandas remain extremely interested in one another, but as Tian Tian's transition to peak was so rapid it was a priority to move straight to artificial insemination first. 'Throughout yesterday Tian Tian remained very quiet and sleepy, but by 5pm there was a behavioural shift and the results of hormone tests that came back at 7pm, carried out by the University of Edinburgh, confirmed ovulation had occurred. 'As each individual panda is different and their pattern can vary from year to year, this is why we start hormone monitoring via urine samples so early and continually observe our female via CCTV as the window approaches. 'Tian Tian is doing very well and everything went according to plan.' Panda reproduction is a notoriously tricky process, with females only ovulating once a year.The gestation period is typically five months and one or two cubs are usually born . Tian Tian stretches after eating her panda cake in her enclosure: Both pandas are said to be extremely interested in one another . The panda enclosure will remain closed until Sunday. Tian Tian (Sweetie) and Yang Guang (Sunshine) are the first giant pandas to live in the UK for 17 years. The animals arrived on loan from China in December 2011 and will remain at Edinburgh Zoo for a decade. There were hopes that a panda cub would be born last year when Tian Tian became pregnant following insemination. Yang Guang feeds on bamboo as he bulks up for the breeding season: Each individual panda is different and their pattern can vary from year to year which is why producing a cub can be so difficult . Yang Guang stands up as he looks into the enclosure of  Tian Tian. Throughout yesterday Tian Tian remained very quiet and sleepy, but by 5pm she had a behavioural shift which meant ovulation was likely . Vets who closely monitored her believe she may have reabsorbed the foetus. Panda reproduction is a notoriously tricky process, with females only ovulating once a year. The gestation period is typically five months and one or two cubs are usually born. The Edinburgh team were assisted by Doctor Wang Chengdong from the China Conservation and Research Centre for Giant Pandas (CCRCGP). Tian Tian (Sweetie) and Yang Guang (Sunshine) are the first giant pandas to live in the UK for 17 years .
Procedure took place at Edinburgh Zoo before an attempt at natural mating . The bears, Tian Tian and Yang Guang, were donated from China in 2011 . Pandas notoriously difficult to impregnate with ovulation just once a year . Tian Tian will be under 24 hour surveillance to monitor the pregnancy .