Our 4th year your track determines how many rotations in a specific area you must do. For example, while everyone does an food animal PMM rotation, FA trackers must do more than one. It is a way for some to really prepare for a job after graduation by getting concentrated hands on experience in one area, while still getting a broad education. For others it is a way to do something fun in school, even though it is not all about what you're going to do after graduation. (I fall into this category, a lot of mixed trackers do.)
But at the end, we'll all be prepared to practice as GP for most species, just as any graduate of another vet school.
Hope this answered your questions
If not, check out our website
http://www.vetmed.vt.edu/acad/dvm/whatistracking.asp