How Much Pasture Does a Horse Need?
By: Dr. Lydia Gray | Updated March 23, 2025 by SmartPak Equine
"Could you tell me how long a horse that gets 2 flakes of hay morning and evening would have to be turned out on good pasture to get the same intake? Thanks!"
- KP, Pennsylvania
Dear KP,
I have a short answer for you and a long answer. I’ll give you the short one first! According to the sixth edition of the NRC’s Nutrient Requirements of Horses, one study concluded that horses need to graze for 17 hours daily to meet their nutritional needs.
So unless your horse is going to be on pasture 24/7, it doesn’t sound like he’ll be able to meet his forage needs on pasture alone.
Can Pasture Alone Meet Your Horse's Nutritional Needs?
Now let’s explore the long answer. How much nutrition a horse gets from grazing depends on many things, including:
- quality of the pasture
- size of pasture (acres)
- stocking density (number of horses/acre)
- species of plants
- maturity of plants
Chapter 11: Feeding Behavior and General Considerations for Feeding Management even says gender, age, breed and number of horses in the herd grazing all effect the grazing rate.
All sorts of interesting facts are shared in this chapter, such as
“Pastured horses move a distance of 2.6 to 3km daily, of which 50-60% occurred during grazing”
and
“Horses are constant feeders. When grazing, a horse takes a bite of grass, then moves forward one or two steps, followed by another bite.”
By the way, this is NOT how my horse grazes! There’s also information in this chapter that you probably already know, for example:
“Infestations of mosquitoes, ticks, horseflies and other external parasites disrupt feeding activities of horses.”
and
“Adult horses appear to have an aversion to eating grass that has been contaminated by equine feces. (roughs and lawns, parasites) Horses have been reported to reject pastures where feces have contacted the grass for longer than 24 hours.”
Ensuring Balanced Nutrition for Your Horse
I love that you’re considering putting your horse on pasture and certainly don’t want to discourage you from doing that. Imagine all those omega 3 fatty acids and all that Vitamin E he will be getting! Just keep in mind that he may still need supplemented with a flake or two of hay per day.
And don’t forget that even on pasture he is probably not getting his mineral needs met, so supplement with a multi-vitamin and mineral or ration balancer specifically made for grass. Oh, and always supply clean fresh water and salt (preferably loose, not a block). Neither pasture nor hay nor grain has enough sodium chloride to meet a horse’s daily requirements.
Video on the Pros and Cons of All Day Turnout
In this Ask the Vet video, Dr. Gray explains the pros and cons of having a horse live fulltime on pasture.
SARAH: Rebecca is wondering what the pros and cons are of 24/7 turnout.
DR. LYDIA GRAY: Oh. So we'll do pros first. And when I think of the pros, the good reasons, for turnout, I think of horse health. I mean, horses are supposed to be turned out. We keep them inside for convenience. So movement is huge, right? Movement helps your joints not be stiff. It helps your hooves with the circulation. It even helps your digestive system. You need movement to get things working and flowing. And you can jump in here any time that you can give something.
SARAH: As a runner, I can relate to movement helping things in a lot of those areas. You know, I think with the joint one, a lot of people think, if my horse is sore, I should probably keep him inside so that he rests. But I think what most people actually see is exactly as you described, that the horse does better and is more comfortable if he's not standing and getting stiff and getting stocked up.
DR. LYDIA GRAY: Correct, yeah. Other pros are if they're turned out together, it could be socializing. They really like other horses.
SARAH: For the most part.
DR. LYDIA GRAY: Horses think horses are cool. Yeah, and they have to know each other. It's healthier as far as fresh air. It's well ventilated in the outdoors.
SARAH: Not a lot of cobwebs trapping a lot of dust.
DR. LYDIA GRAY: Dust and urine doesn't build up. And speaking of manure, it could be easier to clean up if you're turned out on a limestone paddock or something. So any pros I'm missing?
SARAH: Is there, in terms of the movement, not just being good for things like hooves, joints, circulation, is it also beneficial for weight maintenance?
DR. LYDIA GRAY: It can be. I mean, if you're creative in how you set up a food station, if you ask them, use a small hole hay net or something, and put them in different places on their turnout and put a flake in each one, they're going to have to walk to graze. So you're simulating grazing, unless your 24/7 turnout is grazing. And then that's awesome, because horses are designed to meander, to wander, and also to trickle feed, to eat small amounts frequently. So all those are good things.
I thought of another one. If you're not keeping a horse in a stall, it's a money savings, because you're using less bedding. You're not using bedding.
SARAH: You're not using any bedding.
DR. LYDIA GRAY: Yeah. So shall we move to cons?
SARAH: Sure. What's the downside?
DR. LYDIA GRAY: You have to catch them, which, for some horses, can be a problem. So if they're outside, they might be dirtier. So you have to catch and then clean them.
If they're outside, they're probably not going to be supervised 24/7. So depending on where you live, there could be predator-type dangers. Or there just could be-- horses, like we talked with the first question, they're accident prone. They see a fence, and they feel compelled to run into it.
SARAH: I think on the flip side of horses being social animals, too, is sometimes they choose who they like and don't like. And so managing a herd and introducing a new horse is more challenging than just throwing a horse in a stall.
DR. LYDIA GRAY: Yeah. And that liking and not liking does change from day to day sometimes, it seems like. We talked about the manure management. It can be easier or harder in a stall.
SARAH: Certainly, it's less space to cover and to clean up.
DR. LYDIA GRAY: It's a smaller area, but depending on how deep you bed, it can be trickier. And then you have the added cost of it.
SARAH: Plus, if your horse keeps a messy stall, and he's one of those ones who as soon as he poops, he spreads it all over--
DR. LYDIA GRAY: Walks around in it.
SARAH: --and then everything gets dirty.
DR. LYDIA GRAY: Or poops in the water, one of those.
They're less inclined to do that when they're outside.
So bedding. The ventilation, that's a huge con for horses that have a respiratory sensitivity, because it's enclosed. And so the ammonia builds up, and the dust builds up, and it's harder for them to breathe because of all the small particles that are going down their lungs.
SARAH: Aside from the danger, either from potential predators or from each other, due to mood swings, it doesn't sound like there's a lot of cons in terms of the horse's health. It seems like a lot of the cons we're focusing on are on the convenience side.
DR. LYDIA GRAY: They are.
SARAH: So it seems like you're landing on if you can, turnout's--
DR. LYDIA GRAY: I'm definitely landing on--
SARAH: --the best.
DR. LYDIA GRAY: if you can. I understand that--
SARAH: I know you to be--
DR. LYDIA GRAY: --space--
SARAH: --for the turnout.
DR. LYDIA GRAY: Yeah, well, my horse has not been in a stall for three, going on three years now. So I'm a firm believer in that.
SARAH: And it's not because he's not a fancy dressage horse, because he is.
DR. LYDIA GRAY: We do a lot of cleaning and catching. But yeah, I think turnout is the way to go if you can. Realize that not every place in the country and every barn allows it or has room for it. So you are limited by geography at times.
SARAH: But there are things you can do to mimic it if you can't provide turnout all the time, like you were saying, providing the small hole hay net in the stall to make it more like--
DR. LYDIA GRAY: To mimic grazing.
SARAH: The small intake of grazing, making sure that your horse is exercised, especially if he's a horse that tends to get stiff, making sure he gets out every day. So I think provide the turnout if you can. If you can't, do your best to fake it.
DR. LYDIA GRAY: Even if you can't do 24/7 turnout, as much turnout as you can is great, yeah.
SARAH: All right. And I will say on the hard to catch note, on the flip side, that can be a pro--
DR. LYDIA GRAY: Exercise.
SARAH: --because if you-- exercise for humans, I like where you're going. But if you go out to the field and your horse comes up to you, what a feeling. That's love.