I think this depends on the school and on the rest of your application. If the rest of the application is strong, it probably won't matter. Similarly, if you're applying to schools like UC Davis and Penn (which I hear care more about emphasis in your intended area), it may be best to forget about more experiences. However, as someone with a pretty diverse amount of experience especially when it came down to species themselves, I think diversity is important. I suppose if you've done some equine and some 4H/production as well as the intended zoo hours, you're covering yourself pretty well. But seriously, never discount the potential for change in interest. I've gone from equine to LA to equine to lab animal in my "intended career" and I think only just now, after having wanted to be a vet for forever and having had a wide, deep variety of experiences, have I been able to settle. It still may change!
Anyway, to make a long story short, it depends. I would look for those more unique experiences if it were me, but it's up to you 🙂