This may seem like an odd question, but yes, this is what I wanted to know: do the baby cows jump occasionally, without specific reason?
I've built an automatic cow butchery. I have a manual "mercy switch" that lets me save baby cows and return them to the herd - but I failed to use it once, and a baby cow fell into the "lava blade" trap. And... it fit in the 1-block area right under the lava blade, on top of the hoppers. That means, it would get butchered and drop fried steaks as soon as it matures - if it lives that long. Although, the only way it can die now before reaching adulthood is by jumping up, into the lava. I'd have to sit and observe it for nearly 20 minutes to be sure that doesn't happen (and then I still wouldn't be sure if it wasn't just a non-jumpy calf). If they don't jump, I could just scratch the mercy switch and its ramp, and just let the calves await the cruel death coming with adulthood.
(and for a fact, I know adult pigs do jump without good reason. One of them blundered onto my farmland and kept jumping in place until a block converted to soil.)