Every bovine that is fed any grain will daily have a "touch" of acidosis. Some cases are just worse than others. The key is to feed enough roughage, or feed in a manner in which grain is delivered more consistently to the rumen to maintain a more basic ph. God didn't design cattle to eat grain originally so it's up to us to responsibly manage the intake of it. Same as a kid with candy. He'll eat as much as you let him until his stomach hurts. Except with a calf, he physiologically can't eat anymore because the bugs responsible for digesting the feed have died off due to the drop in ph. This stops the feed passage and slows the whole system down. It takes up to 21 days in some cases to build those microbia (bugs) back up to the point of full production and digestion. Of course other things happen when a bout of acidosis occurs (release of toxins into bloodstream causing the laminitis and so on) but you can google that.
Good Luck.