(US,idiomatic) something done immediately, or "from the beginning". Taken from rodeo routine: the bucking bronco, or bull, or the calf for the calf-roping contest is kept in a narrow pen, a chute, until it is released and dashes out to its fate:
His ride on Bold Lancer started out just like he thought it would. The bull bucked straight out of the chute and slowly came around to the left. Clay remained in position, forward on his bull rope, spurs raking the bull’s side. It looked as if it was going to be an easy ride, albeit a low-scoring one. Bold Lancer had other ideas. With only two seconds remaining on the stopwatch, the yellow bull dipped his right shoulder and ducked left. Gravity brutally worked its power on Clay’s upper body, pulling him hard forward and down at the same time.