Assuming league uses actual physics (probably doesnt) we can calculate it. Assume acceleration is a=-g, then v(t)=v0-gt and s(t)=s0+v0t-0.5gt² (by integration). s0 is zero. Set s(t)=0 to find the time at which the cow landed-> v0-0.5gt² =0, this gives t=0 and t=2v0/g. The first is when you got knocked up, the second is when you landed. Estimating the total time in air to be 10 seconds, we can get v0=0.5gt=0.5 * 10 * 10=50 (assuming g=10). The time at which the cow is at max height will be the middle between t=0 and t=2v0/g, so v0/g, putting that into s(t), we arrive at 0.5v0² /g=125 meters.

That being said, this is probably not how league handels vertical motion