The short answer for an adult Orpington
An adult Orpington needs layer feed available all day, not a counted set of meals. An Orpington is a large, soft-feathered, unhurried hen who feeds in relaxed bouts, wanders a short range, rests, and returns to the feeder through the day, and interrupting that rhythm with two brief feeding windows leaves her crop poorly filled by roosting time. Keep a suitable layer ration in the feeder from morning let-out until she goes up to roost, provide grit and shell separately for a laying hen, and let your morning fill and evening check be the managed parts of an otherwise free-feeding day.
A heavy hen whose risk is too much, not too little
The Orpington's feeding problem is the opposite of a flighty layer's, and the meal answer follows from it. She is placid, not very active, and converts generous feeding into body fat readily, and an overweight Orpington lays less reliably and strains her legs and feet under the extra load. That does not mean restricting her to short meals, because she still needs the balanced layer ration, including what goes into shells, in steady small amounts. It means the feeder holds the proper ration freely while the extras around it are controlled: kitchen scraps and scattered grain are the Orpington's real calorie trap, since she will always make room for them and then eat less of the feed she actually needs.
An Orpington day of feeder, range, and rest
Set the feeder in the sheltered part of the run where this less agile hen does not have to compete at speed, and check in the morning that it is full, clean, and not bridged with old feed stuck above the outlet. Give the flock their ranging time through the day, noting that an Orpington will often be the last out and first to settle, and use that observation to spot one who has stopped moving normally. Offer any small treat early in the day and in modest quantity, so the afternoon is spent back on layer feed before the natural pre-roost fill. At the evening check, feel the crop of a hen or two gently as they roost; a comfortably filled crop at night and an empty one by morning is the rhythm you want to see repeated.
Orpington changes that should not wait
An Orpington who stops coming to the feeder in a breed this food-motivated is giving a clear signal, and sitting puffed in a corner, off her feed and not laying, justifies prompt veterinary advice. Lameness deserves early attention in a heavy hen, because sore feet cut her trips to the feeder and the problem deepens as she rests more and gains more. A laying Orpington producing thin-shelled eggs while eating well may simply need reliable access to the separate shell pot, so check that before assuming illness, but persistent shell problems alongside reduced appetite belong in a veterinary conversation. Also confirm the feeder has not run empty for the quieter hens at the edge of the flock's order. If chicken care is shared, KinsLe Care Teams assigns the Orpington morning fill, treat limit, and roost check to named helpers, with each finished job showing its time.