Hay does the heavy lifting, pellets fill the gaps
An adult guinea pig with hay always in front of him is already eating the food his body is built around. Long-strand hay keeps his gut moving in the steady rhythm guinea pigs depend on, and the constant chewing wears down teeth that never stop growing. Pellets were never designed to replace that. They are a concentrated supplement — a way to deliver nutrients that hay alone cannot guarantee, most importantly vitamin C, which guinea pigs cannot make for themselves and must get from food every day.
How much pellet food an adult actually needs
For a healthy adult, roughly 1/8 cup of pellets a day is plenty — about two level tablespoons, or one small handful. Choose a plain, uniform timothy-based pellet rather than a colourful muesli mix. In a mix, a guinea pig picks out the sweet, starchy pieces and leaves the rest, so the portion he actually eats is the least balanced part of the bag. Uniform pellets mean every mouthful carries the same nutrition, and they make measuring honest: the same scoop gives the same amount every day. Younger, still-growing guinea pigs and pregnant or nursing sows are the exceptions — they do better on a more generous, alfalfa-based ration — but a settled adult on unlimited hay needs only that small daily measure.
Getting the daily portion right
Serve the pellets in a heavy ceramic bowl that cannot be tipped, and put them down at a consistent time so the portion becomes part of the day's rhythm rather than an all-day buffet. Topping the bowl up whenever it empties quietly turns a supplement into a main course, and a guinea pig filling up on pellets eats less hay — the swap that leads to weight gain and softer droppings. Freshness matters, too: the vitamin C in pellets fades as the bag ages, so buy bag sizes you will use up reasonably quickly, store them sealed in a cool, dry place, and tip out yesterday's leftovers rather than layering fresh pellets on top of stale ones. A few vegetables alongside — rotated leafy greens and a vitamin-C-rich piece such as bell pepper — round out what the pellets start.
When the pellet bowl tells you something is wrong
Let the bowl inform you. Pellets repeatedly left untouched by a pig who usually eats them, especially alongside reduced hay intake or smaller, drier droppings, is a change worth acting on: guinea pigs hide discomfort well, and a falling appetite can reflect sore teeth or a gut that is slowing down. Contact your vet promptly if your guinea pig stops eating hay or produces noticeably fewer droppings across a day, because guinea pigs deteriorate quickly once the gut stalls. Steady overeating of pellets with a growing waistline is the slower problem — weigh your pig weekly, and if the trend climbs, hold the pellet measure firm instead of letting the scoop creep.
KinsLe's Care Teams helps the whole household feed to the same plan: set the measured pellet portion as a daily duty for your guinea pig, and the person who serves it marks the task complete with a timestamp, so nobody helpfully adds a second scoop an hour later.