I missed that you only have 5 round bales. Feeding by hand --my 2 consumed a 4x5 round of alfalfa/grass mix first cutting in 10 days ( or less) in the worst Winter weather. These bales were stored inside right after being baled so nothing was lost to the elements.
If your hay is stored outside you will get even less.
You need way more rounds. No way would I go into Winter with such little hay.
My two were eating a round bale in a slow feeder net about ten days last winter. My older horse was also eating a bit more than 3lbs of alfalfa cubes per day (50lbs in two weeks).
For every 10C drop below -10C the average horse needs an additional .5% of body weight in forage.
We were running in the minus twenties Celcius for our daytime highs and nudging into the minus thirties overnight last winter. Both horses were partially clipped and blanketed, and lived outside with shelter.
Round bales CAN get very bigāhereās a baler that makes a 5600# baleābut not like bales THAT big are common. OP, just how big (in weight) are your bales? Itās really tough to compare or advise when talking in ābaleā instead of poundsā¦
So 15# twice daily for each horse? Letās call it Nov 1 - May 31, maybe? Might be a little long if thereās pasture, but itās nice to have cushion. Thatās 213 days times 60#s of hay = 12780 pounds of hay. To cover that in five rounds, each one has to be 2500#s.
Thatās possible, I guess. Those would be big bales, but some hay is put up like that.
Didnt expect so many replies so I was absent sorry. It would be 15 lbs average grass hay, 2-3lbs TE, and a flake(honestly no idea what that would weigh yet) first cutting alfalfa twice a day for each horse. The grass hay bales are at about 1500lbs. This was all just a starting plan and to adjust as I see they are reacting but was more so wondering if I should have a different starting plan. My 950lb horse Iām not as worried about as he grew up in this all as he ran the reservation when he was young, my 1100 lb horse came from much warmer weather so he is more my main concern as itās his first winter. The alfalfa Iāve always known to help give them a little extra boost when its extra cold out so thatās why I have so many squares set aside as well as an extra umph if they need it. They will be out until late October to mid November on grass if weather allows and home until roughly April again depending on what the winter is like. We do have mild weather often but itās the cold, cold snaps I want to be most prepped for.
I go through one 400 lb round bale a week for two horses and one pony, all easy keepers, they live out and need the 24/7 hay. I use a slow feed hay net so they canāt waste it. When its really cold one round bale will last 4-5 days.
As long as you have enough hay that you can throw out extra when you need to (super cold) I think youāre on track. You can always add soaked hay cubes or something if you need to.
Iām on Ontario, we get some pretty nasty weather (probably not as cold as ND). I think youāre on track. I canāt speak to the TE though, Iāve never heard of it.
TE isnāt inherently bad, and there are definitely worse feeds out there. But 27% NSC makes it a 100% no for me. Itās supposed to be fed at 4lb/1000lb, so youāre close-ish for the 950lb horse, but short for the 1100lb horse. And there are just much better options with lower NSC. I have no idea whatās available up in SD though.
If you are only feeding a couple pounds and your horses have no known metabolic issues, the NSC is not a big deal since the basis of your diet is forage. There are concentrates that are designed to be fed to easy keepers in small amounts with lower NSC. Triple Crown Lite is fantastic, my horses are really thriving on it, great coats and hoof quality and I do not feed the entire recommended amount. Some people feed by the spreadsheet, trust your horsemanship a bit and really look at your horse. If you can get Triple Crown, their customer service is great and they are always happy to answer equine nutrition questions, and they have been formally educated in equine nutrition.
For what it is worth, my two (one 850-900 and the other around 1100) could chew through a 1800 pound round bale in three weeks in a cold winter. I do suggest you grab a few more bales. If it is native prairie hay, it is more calorie dense than tame hay and even slough hay is better calorie-wise than tame hay. I always fed both and in the brutal Saskatchewan winters, they both preferred the prairie hay over tame, except for alfalfa. I never did commercial feeds, always grew my own grain, and depending if they were in training or just idle, I would add flax. lentils, peas and/or sunflower seeds, depending who had what crop. And that reminds me, IF you can get lentil straw, it is almost identical nutritionally to alfalfa and horses love it
The easiest to find are the typical Nutrena feeds, TE, and occasionally Triple Crown but I wasnt a fan of the TC. I dont think Iāve ever fed the recommended amount for an animal when it comes to that as itās not their only feed source, itās more of an additional something for when they are worked hard or might need the extra oomph in their system, like the cold.