The cattle had been out to pasture when a severe storm came up near the southwestern town of Freiburg and deluged the area with rain and hail Wednesday night.
The animals were pressed together under the tree when the lightning splintered the trunk and sent a bolt of electricity into the ground that killed the animals, police said Thursday. The loss of the livestock was estimated at euro50,000 (US$77,945).
Two of the herd survived the lightning strike.
No injuries to people were reported, although the storm flooded basements and uprooted trees.