What happens if you give an intramuscular injection on cow incorrect?

It depends on what you mean by "incorrect." If you gave a cow an IM injection and injected it in the wrong site, it won't matter. But, if you gave an IM injection under the skin instead or in a blood vessel, it may make the solution you injected less effective than what was instructed on the bottle.

Thus, let it be a lesson to you to always read the label and pay attention to where the best injection sites are. Don't dwell on it: just take it as a lesson learned and move on.