China's dairy industry has the lowest quality standards in the world and much of the blame is down to the large companies that dominate it and the rock-bottom prices they pay farmers for raw milk, said industry experts.

"Milk processors and farmers all know that the problems of low protein content and high bacteria counts in milk are easy to solve with money but they have instead reduced investment because of the low profit margins," said Wang Dingmian, the former vice-chairman of the Guangdong Provincial Dairy Association.

Wang told China Daily on Sunday that, if cows are fed enough, the protein content of the milk they produce would rise within a week. He said dairy farmers have instead reduced the amount of feed they give their animals because of the low price they get from the big dairy companies for the milk they produce.

The high bacteria count in milk is also caused by insufficient capital investment.

"The prolonged duration and high temperature during milk processing has caused the multiplication of bacteria in the milk," he said.

China relaxed its national milk quality standards in 2010, increasing the maximum limit of bacteria acceptable in raw milk from 500,000 per milliliter to 2 million per milliliter and lowering the minimum requirement for protein content from 2.95 grams per 100 grams of milk to 2.80 grams.

Statistics show that international standards for protein content call for 3 grams per 100 grams of milk. The acceptable amount of bacteria in raw milk in Europe is 100,000 per milliliter.

"The revised standards for raw milk, normal-temperatured milk and pasteurized milk were drafted by two Chinese dairy giants - Mengniu Dairy Co Ltd and Yili Industrial Group," Wang said.

Food safety experts claimed the dairy giants helped ensure there were looser standards in place because some of their branch plants could not meet higher standards.

"It's common that branches don't keep up with the standards of the parent company," said Sang Liwei, a food-safety lawyer and the China representative of the NGO Global Food Safety Forum.

In April, 251 children at Yuhe township primary school in Yulin, Shaanxi province, fell ill after drinking school milk manufactured by one of Mengniu's local plants in the province. Test results released later said the milk met China's national standards.

"This shows the national standards for milk quality are imperfect," Sang said.

"A lot of bacteria in milk may mean microbiological problems occur more easily," Sang said. "If companies handling the milk do not strictly follow procedures for the storage and transportation of the milk, there will be food safety incidents."

Wang suggested that a flexible policy be brought in under which high prices are paid to farmers for high-quality milk, so farmers are motivated to ensure their farms produce better quality raw milk.