Tuf Cooper was disqualified for the remainder of the rodeo Wednesday on the grounds of "mistreatment of livestock."
A video of the run shows Cooper striking his horse with his rope while pursuing a calf, which he then fails to lasso.
"The six judges, along with Calgary Stampede officials, unanimously made the decision to disqualify Cooper after seeing him repeatedly and aggressively using his rope on his horse during the run," said Kristina Barnes, a spokeswoman for the Stampede, in an email.
"The Calgary Stampede takes its animal care protocols very seriously and enforces them among anyone who handles animals on Stampede Park, whether its staff, volunteers or competitors."
Barnes said it's believed to be the first time a competitor has been disqualified from the rodeo for that type of infraction.
Cooper is a champion tie-down roper who has earned more than $1 million US during his rodeo career by the time he turned 23, according to the Calgary Stampede's website. His father is Roy "Super Looper" Cooper, a world rodeo champion.