At least four cows have died and many more are injured after unknown assailants trespassed on an organic farm and released the cattle from their pens in the German state of Brandenburg, the Berliner Zeitung reported on Tuesday.

The culprits released scores of dairy cows and young cattle between Saturday night and Sunday morning. The cows proceeded to the concentrate feed area, where they ate up to 10 kilograms (22 pounds) of the substance. Normally, cows only receive a maximum of two kilograms of concentrate per day, the report said.

Read more: Opinion: The German farmers who moan until the cows come home

Four cows died from overdose while 40 others are in critical condition and require veterinarian treatment, according to the report.

"The damage to the liver is just too much," Anja Schiemann, managing director at the Liebenwalder Agrar, told the Berliner Zeitung. "Too much concentrate feed causes the digestive system in the rumen to be severely disturbed."

Police are searching for the assailants

Search for perpetrators

Activists may have been behind the act, the report said, citing social media content. Schiemann's company has offered a €1,000 ($1,160) reward for information that may lead to the capture of the perpetrators. Police are also searching for the perpetrators.

The deteriorating health of the cows is expected to have significant financial losses due to less milk and strict diets of hay, which have gone up in price due to a heatwave over the summer, according to Schiemann.

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