Li Caiwu, a veterinarian at the center with Qiu, was sent to help save the sick panda. But he said Jinyi died before his flight on Feb 9. Until then, the center had been providing assistance by telephone.

"Our center sends veterinarians to all zoos that rent our pandas every six months to conduct normal health checks. The latest check in December showed nothing wrong with Jinyi," he said, adding that a zoo's veterinarians can often heal animals without having to consult the center if the trouble is relatively minor.

Qiu said to better protect giant pandas, zoos from every provincial capital in China usually have at least two to show. Most come from three research centers: Qiu's organization, the Chengdu Research Base of Giant Panda Breeding, and the Qinling Giant Panda Breeding Base in Shaanxi province.

The State Forestry Administration has the final say over which center sends pandas to local zoos, Qiu said. A number of requirements have to be met before a zoo is qualified to rent the animals - the proper condition of the house, the qualifications of the veterinarians and the quality of the food.

"Our center usually sends at least one breeder with the pandas to stay with them at the zoo to coach the local staff how to breed and manage the animals' daily life," Qiu said, adding that the center cannot take full responsibility of the breeding because "one breeder certainly cannot take care of two pandas at the same time."

Qiu said it is normal for pandas to fall sick or die from time to time. It's not necessarily the result of abuse, as some netizens may think, even though China now has more than 300 captive-bred pandas. "No one dares to abuse pandas, nor will our curator allow that to happen," Qiu said.

The panda house at the Zhengzhou Zoo is generally cleaned on a daily basis, but each panda can excrete more than 10 kilograms of waste every day, so it is possible that some visitors will see excrement in the house. But he added that rather than giving off a bad odor, panda waste typically smells like bamboo, the animals' primary diet, though they are also fed a supplemental food mixture.

Given that pandas themselves don't stink, the odor visitors complained about would likely not be coming from the panda house.

"The bread-like foodstuff is a supplemental food for pandas," said Qiu. "Made from rice, soybeans, eggs, carrots and flour, the feed helps captive-bred pandas stay healthier than those that live in the wild, and it's more expensive than bamboo."

Sanitation crucial

Xiong Liangbo, the Zhengzhou Zoo's panda keeper, was sent to the zoo by the conservation center in July to baby-sit two pandas, Jinyi and Wenyu, which had been leased annually for 250,000 yuan ($42,000) each. The pair arrived at the zoo in May 2011. Wenyu was returned to Sichuan for mating, and another male, Longsheng, replaced him.

Xiong complained about what he characterized as a poor living environment for pandas at the zoo. Only a wire net separated Jinyi from the monkey house, and some gibbons also made too much noise, Xiong said. The zoo's authorities said a new panda house is being built so that pandas will not be grouped with other animals.

Xiong said the quality of bamboo the zoo provided to feed the pandas could not be ascertained. He said that several days ago he was looking around the zoo for bamboo that had not been contaminated by pesticides because he had been told that bamboo could not be sent to the zoo because of heavy snow. But he said that even though he is the keeper of the pandas, he has no say about their food supply.

"Bamboo is the main food for giant pandas," Xiong said. "For more nourishment, we also give them concentrated feed, but without enough bamboo, pandas cannot digest this feed properly and they excrete it directly."

According to Li Chaojun, the animal management department head, the zoo was transporting fresh bamboo every day from Xinyang, more than 300 kilometers south of Zhengzhou. Li said that one panda consumes 40 kg of bamboo daily, in addition to 1.5 kg of fresh fruits and vegetables - apples, carrots, bamboo shoots - and 1 kg of concentrated feed, a cake made of a mixed powder of minced meat and ground beans.

Xiong said Jinyi's weight dropped 20 kg by the time she died at the Zhengzhou Zoo, a significant proportion for an animal that originally weighed 90 kg. But Li insisted that Jinyi had not been abused. Zoo personnel "tried their best to guarantee the interest of pandas", Li said.