Even if I hadn’t already decided to answer commenter Acyn’s question and talk about horses in winter, the universe would have made sure I will do exactly that. First as I was avoiding work—er, noodling on twitter, I came across this delightful thread, not about horses but about emus in winter. And then as I pulled myself back to the blank page, an email came in with a link to an equine nutritionist’s article on—yes, horses in winter.

Dr. Thunes offers a concise checklist for horsekeepers in a colder climate, specifically the UK or the northern tiers of North America. She happens to have migrated south, to a city just a couple of hours’ drive from my horse farm outside of Tucson, Arizona. It’s a good checklist, aimed at the experienced horse owner, but worth a look for what it has to say about what horses need as the season changes from warm to cold.

We’ve had an unusually warm year here, and it still feels like late fall rather than the gate of winter. Yet there are indications of change. It was over 80F/20C on Monday. By Friday morning, the temperature will hover around freezing, preceded by a spate of cold wind and rain. Even in regions where the range isn’t quite so dramatic, there’s still a point at which the barn manager has to switch over from summer to winter horsekeeping.

For some that’s an actual nomadic operation: moving the herds from the summer to the winter pastures. From lush grass (now thoroughly grazed down) and relatively cool temperatures and free access to water, to such grazing as the climate will support, relative warmth, and shelter from the winter storms. The horses will be carrying extra weight, if possible, to help them through the leaner months; and thick, one-to-three-inch/2.5-7.5cm winter coats will be replacing their flat, sleek summer attire.

In more settled areas and cultures, the migration will amount at most to a rotation of pastures, a shift of the herds closer to the barns. But many stables don’t have that much land, or the luxury of moving the horses from their established pastures and stalls. When winter is something to be adapted to on the spot rather than avoided as much as possible, horsekeepers do what they have to in order to keep their charges healthy, fed, and protected from the weather.

In warm weather, horses are generally cheaper to feed. They can survive all or partly on grass pasture, as they were evolved to do, and may be supplemented minimally if at all depending on the quality …….

Source: https://www.tor.com/2021/12/13/writing-horses-horses-in-winter/