This is the harrowing moment a distressed elephant collapsed while being beaten and forced into a truck in Thailand. The male jumbo named Plai Tongkhun had a mahout on his back wielding a bullhook to make him walk up the vehicle in Surin province, northeast Thailand.However, testosterone-fuelled Plai Tongkhun became irritable because of the current mating season which lasts until the end of December and early January.Footage from the incident on November 17 shows how the agitated jumbo repeatedly rammed its head against the side of the truck. It then fell off the ramp and apparently lost consciousness.Shocked onlooker Sujitta Jumjit said: 'Plai Tongkhun was in musth so the caretakers were trying to get him back to the camp. 'One of his eyes was blinded from the liquid that is secreted during musth so I guess he must have lost balance and fallen off the truck while being irritated at everything around him. 'Nobody was seriously injured and Plai Tongkhun is now resting at the camp safely.'Male elephants or bulls periodically enter a state called ‘musth' which can last several months. A bull in musth experiences increased testosterone production and aggressive behaviour, resulting in clashes between adult males.Elephants are Thailand's national animal. The country has an estimated 2,000 Asian elephants living in the wild, where they wander freely among protected forests.In the wild, they roam through the deep jungle and in the country's protected national parks but often encounter humans on roads and in villages. However, they are protected by laws and killing them carries a maximum prison term of up to three years and a fine of 1,000 baht (25GBP).A similar number of elephants are kept in captivity where they work in the tourist industry or are hired out for religious festivals and weddings.Animal rights groups such as People for the Ethical Treatment of Animals (PETA) continue to campaign against elephants being kept in captivity.