I could possibly add some sunflower seeds to the ration mix in the future, but I feel like neither one of them could use any extra weight, especially Zeppy. She definitely is more robust. I think Coco falls right in the middle and I can feel her spine and hip bones with just a tiny bit of pressure. Zeppy on the other hand, hers are a bit harder to feel. She has always been easy to keep weight on. Up until about a week ago, they were getting some basic grass/clover mix hay that is harvested where I grew up. It just kinda grows wild, almost like a prairie grass mix. Like nothing is done to cultivate or manage it, it's just grown and cut a couple times a year, plus 2 cups once a day of timothy/alfalfa pellets. They could also graze our overgrowth woods/brush when things were green. They kept a healthy weight easily.