0 C isn’t cold enough to harm cattle. Crop failure can result from prolonged cold, and cause starvation, but the cattle would most likely have become burgers and steaks long before that.
By February 17, the spell had killed a total of 59,962 cattle in the region, including 7,349 in Ha Giang province, 6,400 in Lao Cai and 5,571 in Bac Can province...