Police are investigating after a four-day-old calf was killed with a screwdriver through the eye.
Officers were called to the field in Bromholme Lane, Brampton, near Huntingdon at 2210 BST on Tuesday.
The screwdriver was seized, but the calf's mother had licked it, removing any potential fingerprints.
PC Simon Page said: "This was a shocking and despicable act and we would appeal to anyone with information to contact us urgently."
Farmer Basil King, of Rectory Farm, Cambridge Road, Godmanchester, said he was horrified by the attack and was offering a £2,000 reward to find the culprit.
'Killed for meat'
He said a calf had disappeared from the same field about five weeks ago.
"This one was found in the field with this horrific injury to its head," he said.
"It was left there, I believe, because the mother of the calf is quite an aggressive animal and saw off the people who did this.
"I believe they were intending to collect it at night for meat."
Mr King said the animal was from a predominantly beef herd and both it and the calf that previously disappeared would have been born "with meat on them".
He added: "I believe there are people in the community nowadays who probably weren't in the community a few years ago who will take this sort of thing for food.
"We deal with livestock - we've had stock on this farm for 30 years - and we see all sorts of things in that line of work but it kept me awake all night due to the extent of the injuries."