Transitioning from Hay to Green Grass

Hello. I am planning on moving horses from hay only to pasture boarding in a green grass field. It is winter but the grass is still lush and green and I don’t want to risk colic or founder. I know it is recommended to graze for 15-20 minutes at first and slowly increase grazing time each day but I have nowhere to put the horse that doesn’t have grass.

Would it be okay to put the horse in a round pen (~45 feet in diameter) for a week or two before turning him out to a 0.1 acre pasture or will the round pen still provide too much grass for the horse? Would mowing the round pen before the horse arrives make it such that the horse would not have too much grass?


Any chance to keep horses in stalls while they transition onto grass? Because even the grass in the round pen could be too much.

Where are you located? Green lush grass down in Texas this time of year is a whole different story than grass up in Rhode Island right now…

I’m located in North Carolina.

You could put him in a small pen (with some hay) and gradually add panels.

I think I would use the round pen with a muzzle for a day or two, then no muzzle for a few days. I would then transition to the field during the day and the round pen at night for a few days.

I am in NC and, my fields have been seeded with winter rye. Due to the cold snap we had about 2 weeks ago, the winter rye is negligible this year – I am amazed that you have green and lush grass!

The guidelines for putting a horse on grass differ depending on the sugar content in the grass. Fast growing, late spring grass has a high sugar content, as does early morning grass. That is why you see/hear of horses foundering in the spring. Same is true of horses who are not used to grazing being turned out 24/7 when they can eat the early morning grass.

At this point in NC, I would let them graze and eat pretty much whatever they want. Winter rye does not contain a lot of sugar.

Again, I am amazed at the grass you have. I have 2 horses on 5 acres and another 2 on 4 acres and they have pretty much eaten all the stems and are now kept busy with nibbling, which is why I continue to feed hay all winter. The grass we have now looks good and gives the horses something to do all day, but it does not contain all the nutrients that a horse needs.

Winter rye has the potential to be the highest grass in sugar content of ANY kind of grass. Especially under sunny, cool conditions.
Be VERY careful introducing horses to rye.