The RSPCA dubbed Roger Baker "the cruellest farmer in Britain"

Roger Baker, 61, was found guilty in January of attacking Jonathan McCulloch and Susan Potter on his land at Ventongimps, near Truro, last year.

Baker, described by the RSPCA as "the most consistently cruel person" they had dealt with, had denied the attacks.

Sentencing Baker, Judge Stephen O'Malley described the incident as a "deliberate and violent attack".

The jury at Taunton Crown Court had failed to reach a majority verdict on a second charge of making a threat to kill Mr McCulloch - a charge Baker also denied.

Vet Sue Potter had to hold her breath under the slurry

The charge was instead left to lie on file at the request of counsel for the Crown, Michael Brabin QC.

Baker was found guilty by a jury of running at Mr McCulloch, who works as an animal health inspector for Cornwall County Council, and government vet Mrs Potter on 25 February last year.

Mrs Potter, 47, and Mr McCulloch, 27, were videoing a dead lamb and emaciated cattle on Baker's land when the attack took place.

Baker, who lived in a caravan on his land, came "out of nowhere", running at full speed to attack the two officials in his slurry-filled farmyard.

He first grabbed Mr McCulloch by his overalls, dragged him across the yard and attempted to dunk him in the putrid liquid - consisting of mud, animal faeces and urine.

As Mr McCulloch shouted for help, Mrs Potter went to assist her colleague.

Jonathan McCulloch and Susan Potter were videoing farm animals

Baker, who was "very, very angry", grabbed Mrs Potter by the neck, pulled her to the ground and dragged her into the mire.

The court heard Baker, a sheep trader, had convictions for animal cruelty spanning 30 years.

In 1999, he was jailed for five-and-a-half months for abusing dozens of animals and was banned for life from keeping livestock.

Defence barrister Robert Linford asked the judge to take into account Baker's increased levels of co-operation with the Department of Environment, Food and Rural Affairs.

Sentencing, Judge O'Malley said: "You attacked two animal health inspectors who were visiting your farm, two inspectors simply doing their job when you came charging at them.

"It was a repeat of violent behaviour - behaviour for which you had already been sent to prison."