I decided to do a little searching myself, now that I'm at my PC. In 1984 there was 13 killed from derailment from hitting a cow, but that was a "push-pull" train and it wasn't the locomotive that hit the cow, but a much lighter "control car".[1] Another case where the train hit a cow and launched it through the air, and it struck and killed someone.[2]

Also, in [1] there weren't any cowcatchers on the train either. All the trains (besides possibly an old steam locomotive, IDR) that I've seen in my life have cowcatchers and also a locomotive in the lead.

[1] https://mx-schroeder.medium.com/unholy-cow-the-1984-polmont-... [2] https://morningsidekick.com/indian-man-killed-in-freak-train...