So there's a couple ways to do a "mixed" curriculum. A truly mixed curriculum takes some time away from your 4th year rotations so you can sit in with the class below you on whatever subject material (large or small) you didn't take the first time. So you get the classroom learning but miss out on some weeks of rotations - UNLESS you choose to stay an extra semester to do more rotations (which you can do, you just have to pay more money). One thing that a few people who want to do small animal/equine or similar large/small mixed is they'll pick a track (small animal) but take several large animal rotations 4th year. This works well especially if you have previous medical experience in those areas.
In terms of your interests - you could probably track large animal food and then take some of the electives offered (there's an avian/reptile, small lab animal, and poultry, plus a small lab mammal) plus add in those rotations in 4th year. Check out the general scope here -
UC Davis School of Veterinary Medicine
To be absolutely sure, I would call and talk with admissions tomorrow about all this - explain your interests and make sure they say "yes" because sometimes things change. But for the most part, people like you who have diverse interests seem to be able to get all the information/experience they need/want, just sometimes it takes a little juggling.
There are also opportunities to gain experience as a 1st-3rd year--there's a number of student jobs for large animal, plus CAPE (the exotics/wildlife division of the teaching hospital) treatment crews where you can get experience working with patients. There's also a raptor rehab center on campus, a primate center involved in research, and a sea bird rehab center nearby that a few of my wildlife friends go to. There's also a pretty active wildlife and exotics club.
Hope that answers your questions. Feel free to message me if you have any more in the mean time. Either way, congrats on getting in!