I think a very important question for applicants to be asking themselves is not only 'what do schools value/ look for in experience" but "why do they value these experiences?" I can't understand how someone can be sure they want to go into vet med without having a lot of experience in the field (be it research or clinical practice, etc.) For me, my first 2 years as a tech in a small animal clinic taught me so much more about what I don't want to do than what I do want to do. The requirements for experience aren't just about jumping through hoops, they're for your own benefit and will really help you with school selection (ie to track or not to track) and fine tuning your education to where you want to be when you finally get your DVM. So definitely go for a very diverse experience 'portfolio' because it will make your app stronger but most importantly you won't spend 4+ years and a whole lot of debt to find out you don't like where you've ended up.
(and off the soapbox)
I was told I had very diverse experiences- so in addition to working as both a SA and LA tech (vet experience) I had zoo volunteer, sunbear reproductive research, cancer research (on mouse models), shelter volunteer, farm worker, wildlife rehab, and wildlife field research. All of these are animal (non-vet) experience and were looked upon favorably. Find something you think is fun, that is the key to having positive volunteer experiences.