Is this healthy or fatty for my horse, for all those horse lovers!?

This is something we give our mare for breakfast and tea but may just start to give it her in the afternoons. We give her a handful of chaff, a carrot or two to cut up, also one apple cut up. Then we give her two frisky mare calmers and magic calmer(hyper horse) and some garlic flakes, around about a little sprinkle. I wanted to know if those is fattening, she is a welsh cob and I see other horses having breakfast and teas but not sure if the breed she is is suitable with this food? Any ideas? Best answer included. This will help a bunch!