Went down a long and winding rabbit hole and stumbled upon this:
Scientific studies have been conducted to determine if cow tipping is theoretically possible, with varying conclusions. All agree that cows are large animals that are difficult to surprise and will generally resist attempts to be tipped.
And so now you know as well. Source (such as it is): https://en.wikipedia.org/wiki/Cow_tipping
Also, should you be planning on attempting a cow-tip:
Estimates suggest a force of between 3,000 and 4,000 newtons (670 and 900 pounds-force) is needed, and that at least four and possibly as many as fourteen people would be required to achieve this.
So make sure you have enough people with you.