I have some alfalfa pellets that look like that..they are larger than regular pellets, kind of shiney, and are just called alfalfa treats. Granted, they've been sitting in the baggie they came in for about a year now...
Is that the actual feed you get from your vet? There really is no way to tell just by looking at pellets, because pretty much all the chin-safe pellets look the same. There's no way I could tell the difference between Tradition, Oxbow, and Mazuri if you mixed it all together.
I would call your vet and ask..I doubt anyone can tell you what it is just by looking at it.