Changing your horse's hard feed is not like swapping one bag for another and carrying on as normal. The microbes in the hindgut that ferment his feed are tuned to what he eats now, and they need time to adjust to anything new, which is why a gradual introduction over at least a week to ten days protects him from loose droppings, gas and the digestive upsets that can follow a sudden change.
A step-up schedule that works
Keep the hay or haylage exactly as it is and change only the bucket feed. For the first two or three days, mix roughly a quarter of the new feed with three quarters of the old. If droppings stay firm and he eats up happily, move to half and half for two or three days, then three quarters new to a quarter old, and only then feed the new ration in full. Horses with sensitive digestion, a history of digestive trouble or a big difference between the two feeds do better stretched over a full fortnight. Change one thing at a time: if the forage is also changing, settle that first and let a few days pass before the bucket feed moves.
Weigh the mix, don't scoop it
A quarter of a scoop is not a quarter of a ration, because feeds differ in density and a scoop of one can weigh half as much again as a scoop of another. Keep a cheap kitchen scale in the feed room, weigh the old ration and the new one, and work out the mixed weights for each stage of the changeover. Write the weights on the bin or the feed board so the quarter stage really is a quarter, whoever is mixing. This matters most with concentrated feeds, where a heaped scoop can quietly double the intended amount.
Read the droppings as you go
Your best feedback comes at mucking out. Slightly softer droppings for a day often settle on their own, but if they loosen properly, hold the mix at the current ratio for a few extra days rather than pushing on, and only step up again once things firm up. Watch appetite too: a horse who picks at the new mix may dislike the taste rather than the change itself, and a slower blend usually wins him over. Keep an eye on water intake and note any change in behaviour or energy alongside the droppings.
If he has never had hard feed before
A horse coming off grass or forage alone onto bucket feed for the first time needs the longest runway of all. Start with a small handful in a bucket so the taste and the routine are familiar, then build the amount in small steps over two weeks or more while the forage stays constant. The goal is a gut and a horse who both regard the new feed as unremarkable by the time the full ration arrives.
When to stop and take advice
Stop the changeover and call your vet the same day if your horse goes off his feed altogether, stops passing droppings, or shows signs of discomfort such as pawing, rolling, looking at his flanks or sweating without work. Those signs matter far more than the feeding plan, and they should never be waited out overnight. A horse who repeatedly fails to settle on a new feed also deserves a conversation with your vet or an equine nutritionist before you try again, because the feed itself may simply not suit him. Writing each day's mix into your KinsLe Care Teams duties means anyone feeding that week follows the same step-up, so the transition stays gradual even when you are not the one holding the bucket.