The group of seven men and one woman all pleaded not guilty in a Kingston, Ont., court to a single charge each of mischief over $5,000.
They are accused of blocking trucks carrying cattle to auction from Frontenac Institution during protests in August 2010.
Police arrested 24 people over two days of demonstrations but many accepted a deal to give a donation to charity through the direct accountability program.
The demonstrations began after the Conservative government decided to close Canada's prison farms — including those at Frontenac and Collins Bay Institutions in Kingston — in what was known as the Save Our Prison Farms campaign.
The group launched a Twitter account and website trying to garner support to keep the farms open, including from the federal opposition parties.
Supporters of the prison farm program said a strong work ethic and sense of responsibility were among the skills developed through the initiative.
Before the trial began Monday, Judge Rommel Masse asked each defendant to sit in alphabetical order in the area typically reserved for defence lawyers. The move resembled a game of musical chairs and drew laughs in the packed courtroom.
The audience also found other portions of the proceeding humorous as the defendants huddled during cross examinations or passed notes to co-defendant Andrew McCann, who led the questioning of the Crown's first witness, Kingston police Staff-Sgt. Lillian Walcer.
Walcer, who acted as the police liaison during the demonstrations, testified the defendants were warned Aug. 9 if they crossed cement barricades to block cattle trucks attempting to leave the institution they'd be arrested for mischief.
The previous day they were able to stop trucks from entering the institutions.
But McCann, a baker, pointed to Walcer that none of the defendants on trial crossed the barricades, but were pulled from the crowd by police and arrested.
Walcer said police "interpreted" risk, including when several of the defendants began walking quickly towards the entrance through a crowd of protesters with devices known "sleeping dragons" attached to their arms. Sleeping dragons can be used by demonstrators to lock themselves together or to a immovable object.
Police video showed they never were able to reach the entrance before being arrested some three metres deep in the crowd.
McCann said at no point were the trucks impeded and video showed the first truck going through easily.
Co-defendant Ian Stutt, a farmer, is shown on video being pulled over the barricade by several police officers with a sleeping dragon attached to his right arm. Once over the barricade, he sits down.
"Would you confirm he (Stutt) lifts his leg co-operatively?" McCann asked Walcer when video showed Stutt lifted his left leg to assist officers picking him up from the ground.
This also drew laughs from the audience.
"Is it illegal to sit down?" McCann asked.
Masse interrupted and told McCann to rephrase the question, prompting more laughter.
Walcer said sitting down could be deemed as being unco-operative but later added police had no reason to believe the protesters would turn violent.
About a dozen protesters rallied outside the courthouse Monday, holding placards with messages such as "Harper is a Bully!" referring to Prime Minister Stephen Harper.
Also charged are Jesse Archibald, Gerry Capelle, James Masse, Thorsen Hansgen, Lindsey Pilon and Patrick Thompson.
The Crown withdrew mischief charges against 87-year-old Olga Hudson and Diego Bank on Monday.
The trial is expected to wrap up Tuesday.