"It's time for all the trainers and jockeys who are against jumps racing to speak up and have it banned," he said. "It's barbaric and it has no place in the 21st century.
"If the people who run horse racing in SA think this is a good look for racing, then they'll oversee the death of the sport overall."
The RSPCA, on Sunday, said it was the fourth fatality at Oakbank in the past six years, after a horse died in a trial race in 2014 and two horses were put down in 2012.
A further three horses died at Oakbank in the two years prior to 2012, RSPCA South Australia campaign co-ordinator Carolyn Jones said.
Late last year, a parliamentary committee recommended that jumps racing should not be banned and the issue "should not be revisited by Parliament for the next three years".
Oakbank Racing Chairman Barney Gask said members of that committee "spoke to all stakeholders and they saw fit for jumps racing to continue".
Greens MLC Tammy Franks still has a bill before state parliament to ban the style of racing.
Up to 50 members of the Coalition for the Protection of Racehorses were to protest at Oakbank on Monday morning .
"Every time something like this happens, it just re-inforces that jumps racing can't be made safe," organiser Elio Celotto said.
"It just makes us more and more determined to bring this sport to an end."