KYIV/HAMBURG, April 11 (Reuters) - Chinese buyers have cancelled shipments of Ukrainian-origin animal feed corn together totalling several hundred thousand metric tons, traders said on Thursday.

The precise volumes were unclear, but some traders spoke of about 300,000 tons cancelled in up to five Panamax shiploads which had previously been bought for April/May shipment.

Most of the cancellations were in the last two weeks, traders said.

Panamax shipments from China to Ukraine are typically about 60,000 metric tons.

One German trader, speaking on condition of anonymity, said China was understood to be seeking to limit corn imports to support Chinese farmers "in the face of current low prices".

Ukraine is a major corn supplier to China. A total of 600,000 tons of corn could be exported from Ukraine to China in April and 400,000 tons in May, Ukrainian brokers said on Wednesday.

A source in Ukraine familiar with the matter said Chinese consumption was falling while warehouses were full and that the reluctance to import did not just apply to Ukrainian grain.

"It seems that companies have been advised not to fulfil contracts, but this applies not only to Ukraine, but to all supplies in general," said the source, who also could not be named because they were not authorised to speak publicly.

China cancelled purchases of about 1 million tons Australian wheat and 500,000 tons of U.S. wheat largely because of falling prices and a slower rate of economic growth, traders said in March.

Corn prices remain close to three-year lows hit in mid-February as U.S. inventories are expected to be high.

The U.S. Department of Agriculture (USDA) in its world supply and demand report later on Thursday is expected to forecast high season ending U.S. corn stocks. (Pavel Polityuk in Kyiv and Michael Hogan in Hamburg; additional reporting by Gus Trompiz in Paris; editing by Barbara Lewis)