We will hopefully be taking posession of our new farm in the middle of July. There hasn't been horses there for a very long time and right now there's basically one giant field that's planted in hay (timothy and alfalfa). While eventually the plan is to plant a horse pasture mix in the summer fields, in the short term is it ok turn horses out in a field that's mostly alfalfa? Is it going to make them sick?
I know a lot of people, myself included, that feed alfalfa hay as part of the total diet. That said, are your horses currently eating free-choice alfalfa? Because that's pretty much the same as turning them out in alfalfa-rich pasture. Alfalfa is very tasty, so they're likely to eat that first.
So, yes, it is a very rich diet and could easily cause problems. And, especially if you have easy keepers, you're looking at risk of obesity and founder. Some options might be limited turnout while making the rest of their diet be plain grass hay, ditto using a small portable corral to limit how much of the field they can access at a time, and using a grazing muzzle.
Not a grand idea in general. Hay crop type alfalfas vs grazing type alfalfas come into play. Grazing type alfalfas are added into pastures at a much lower plant population not to mention those types of alfalfa are selected to handle the traffic (at the expense of top yields). I see sausage shaped horses in your future.
Timothy in general is not the best to be horse grazed as traditionally being bitten off at the ground causes too much stress on it. But there are varieties out there that claim to deal with this. I do not find them productive.
So if you plan on grazing this limit grazing would be wise. Either build them up slowly and severely limit time....maybe even add muzzles. Or set it up like a stripgraze system so they eat a little and effectively kill it as they go. Or chat with a local crop specialist and have them stop by for a look see. The answer may be a simple as spraying a selected grassier area with a herbicide that will knock back the alfalfa but allow you to graze continue to graze now. It will kill the timothy eventually too as the horses over graze it but you can reseed with better pastures blends as planned then.
Keeping your pasture mowed will help alot. Little bites instead of big ones. Only detriment is for insulin resistant horses, more sugar if mowed really short. But if you have IR horses, you wouldn't want to put them out on such rich pasture.
We had straight alfalfa planted on our place when we built our house/barn etc, we disked it out and planted grass. We have a few random alfalfa plants that come up, but after 16 years its pretty much all grass with some normal weeds.
All alfalfa pasture is very high protein and while we didn't have a problem, the neighbor had bloody noses. I think it was from having stems poke their nostrils while grazing, but she thought it was "protein poisioning" which I have never heard of.
I would have someone cut it for hay first. Let it recover and use it sparingly, if you have too. Is this going to be your main source for hay to feed your animals? If so you don't want them to mess it up. Alfalfa is rich enough as a hay ( i feed it too) and in pasture form much more than I would want my horses grazing on. Just my thoughts.
You don't want to turn your horses out on it. if you ever want to cut it for hay. Around here, we don't even ride through hay fields. They will trample it and eat it, and it will be ruined; you will have to till and replant when you decide to cut.
Best to cut it now, and keep the horses off it. It isn't for grazing.
They snooze, they munch hay -- oh the abuse! The humanity!!! Won't someone think of the children! - rhymeswithfizz
Our horses live out on 140ish acres, which is about 80 acres of hay field. When its shorter, they eat it. When it grows, they move to the shorter, mowed spots. We get at least 2 cuttings off of it every year. I would estimate 40 round bales, and 150-200 square bales each cutting (ROUGH estimate).
We have never had a problem with keeping them on it, except that we have to dry lot so they dont get fat.
ETA: ours is NOT alfalfa...you may want to limit intake of that more.
Charlie Brown (1994 bay TB X gelding)
White Star (2004 grey TB gelding)
It sounds like it's safest not to turn them out on it. They haven't been eating much alfalfa as it is, so turning them out on a field of almost pure alfalfa sounds dangerous. There is a small 2 acre grass field I can put them on this year until I can plant a proper pasture area for them. Thanks for the advice everyone.