Commercial Feed vs. Non-Commercial Feed? (That is the question.)

[Scribbler]

@Losgelassenheit;8450659

For instance, the largest horse in moderate work took approx 10-12lbs of it, but looked fabulous. I was originally happy with the idea that we could feed less of the whole foods while the horse still received the same, if not more nutrition, but now having to increase the amounts, we are getting back up there to the limit of just how much I’m comfortable pumping into a horse, especially now dealing with a whole grain. The same horse, I’ve been told, cannot go any higher than 3 lbs per feeding, and that’s where we are right now (not counting the addition of the supplements).

When you say the horse can’t or shouldn’t go higher than 3 lbs per feeding of a whole grain, what do you mean by grain? Do you mean that the horse can’t go higher than 3 lbs of whole oats per feeding, or that the total mash size including alfalfa pellets can’t be more than 3 lbs?

It is true that you don’t want to overload the gut at any one time with too many high-starch oats. But then you wouldn’t want to overload the gut with too much high-starch extruded feed either.

However, alfalfa pellets or cubes, and beet pulp, are not grains; there’s no upper limit to what you can feed; in some cases (toothless old horses), these can form their entire diet.

If you have gone from 12 pounds of grain-based extruded/pelleted feed to a mash that is maximum 3 pounds of alfalfa cubes/oats, then there would be a big drop in calories.

If you feel that you want to feed more than 3 lbs of oats, then you can feed oats twice a day.

Also, are your horses getting enough hay? If they are losing weight, they should be on free-choice hay.

I also wonder, from the nutrition point of view, why feed alfalfa cubes if you are also feeding a good timothy/alfalfa mix? What are the cubes doing that the hay is not doing? Maybe switching to beet pulp would be useful, and add a different nutrition profile?

[Losgelassenheit]

[QUOTE=JB;8450771]
The ailments improved most likely - and this is me guessing - because you removed allergens - soy, corn being the more likely culprits. Or at least removed them in significant amounts (allowing for the presence of some in the v/m, and maybe the RG, I can’t recall offhand its fortification.

Me? I’d go back to a commercial diet, but a better quality one. TC in general is better than Purina (IMVHO), though not all of their feeds are ones I’d consider. TC Sr is very nutritious though lower in fat than Ultium (higher than Strategy) but I don’t believe in the “gotta feed fat” thinking that many do, so unless a horse tells me otherwise, I don’t bother striving for high(er) fat, and has known ingredients. Even TC Complete is better than Strategy.

You have many options for feeds better than Strategy (which in particular is notorious for “my horse looks fantastic!” vs “my horses look/feel/act like crap!!”, for whatever reason).

What brands do you have access to?

How much of each of the new ingredients are you feeding, and which v/m are you using?[/QUOTE]

Thanks, JB. Very insightful. Sorry, I did reply to you earlier, but my internet ate the post which was quite lengthy and I just haven’t had the energy to re-write it all. I will do my best to paraphrase what I remember now…

I do agree that removing the corn, soy, molasses, etc., likely contributed to the improvements seen. The vit/min is ADM GroStrong top dressed. The Renew Gold is all non-GMO, rice bran and coconut meal (Cool Stance).

Unfortunately, I will have to respectfully disagree on the TC products, at least in our experience. TC Senior was the very first thing we went to once the Pennfield quality slipped, and I have never had to peel such typically calm horses off the ceiling like I did then. Vet and rep said that it was likely a soy sensitivity presenting the issue. Switched to Nutrena and they all came down from the clouds. Of course they then discontinued the complete feed we were using with fairly good results. Out of desperation we went back to the new Pennfield, more specifically Fibregized Omega, which according to that rep was going to remain unchanged through Nutrena. Within 4 weeks we were seeing ribs, and we then consulted with Cavalor and Purina both of whom didn’t understand why they recommended the Fibregized with it being half the calorie content of what we’d previously been feeding. Cavalor had just about every horse on a different variety of their feed, so we went with Purina, and believe me when I say it was a last resort. I even cringe now when I say that everyone looked the best I’d EVER seen. Things were going swimmingly, until about 8 months in, which is when we started to see issues arising.

We have access to just about every brand under the sun. To date, the only brands we haven’t tried yet are KER and Seminole Wellness, which I have heard great things about.

Again, it’s difficult to break down the amounts of each ingredient per ration, per each of 13 horses. The largest, and the one that is struggling most is a (should be) 1200 lb 17h warmblood currently getting 6 lbs/day. Broken down it is 3 lbs of the base (1 1/2 lbs whole oats, 1 1/2 lbs alfalfa pellets), in addition to 2 cups Renew Gold, 1 cup fresh ground flax, 1 oz v/m, and 2 tbsp spirulina. This gets soaked with an equal amount of alf cubes for the PM meal.

Portions lower in relation to size. Generally speaking, we have smaller horses (15.3-16.2) on 4 lbs/day. Large ponies on 2.5 lbs/day, mediums on 2 lbs/day, and smalls on 1-1.5 lbs/day.

[Losgelassenheit]

[QUOTE=Scribbler;8452711]
When you say the horse can’t or shouldn’t go higher than 3 lbs per feeding of a whole grain, what do you mean by grain? Do you mean that the horse can’t go higher than 3 lbs of whole oats per feeding, or that the total mash size including alfalfa pellets can’t be more than 3 lbs?

It is true that you don’t want to overload the gut at any one time with too many high-starch oats. But then you wouldn’t want to overload the gut with too much high-starch extruded feed either.

However, alfalfa pellets or cubes, and beet pulp, are not grains; there’s no upper limit to what you can feed; in some cases (toothless old horses), these can form their entire diet.

If you have gone from 12 pounds of grain-based extruded/pelleted feed to a mash that is maximum 3 pounds of alfalfa cubes/oats, then there would be a big drop in calories.

If you feel that you want to feed more than 3 lbs of oats, then you can feed oats twice a day.

Also, are your horses getting enough hay? If they are losing weight, they should be on free-choice hay.

I also wonder, from the nutrition point of view, why feed alfalfa cubes if you are also feeding a good timothy/alfalfa mix? What are the cubes doing that the hay is not doing? Maybe switching to beet pulp would be useful, and add a different nutrition profile?[/QUOTE]

The whole food nutritionist said not to go any higher than 3 lbs of the mix per feeding. It was suggested I give another lb of oats at lunch if I really felt the horse needed, but 3 lbs was the absolute max of the mix per AM/PM feeding. The horses get the appropriate weight of hay, but I will say with hay at $16-20/bale, it is difficult to feed it free choice! Hence why we stretched with beet pulp in the past, but when the issues began popping up, we switched to alf cubes. I suppose we could try the beet pulp once again. We have just been leery, since we pulled the feed and beet pulp at the same time, there’s some uncertainty where exactly the issues were stemming from.

[yourcolorfuladdictio]

[QUOTE=Losgelassenheit;8454317]
Thanks, JB. Very insightful. Sorry, I did reply to you earlier, but my internet ate the post which was quite lengthy and I just haven’t had the energy to re-write it all. I will do my best to paraphrase what I remember now…

I do agree that removing the corn, soy, molasses, etc., likely contributed to the improvements seen. The vit/min is ADM GroStrong top dressed. The Renew Gold is all non-GMO, rice bran and coconut meal (Cool Stance).

Unfortunately, I will have to respectfully disagree on the TC products, at least in our experience. TC Senior was the very first thing we went to once the Pennfield quality slipped, and I have never had to peel such typically calm horses off the ceiling like I did then. Vet and rep said that it was likely a soy sensitivity presenting the issue. Switched to Nutrena and they all came down from the clouds. Of course they then discontinued the complete feed we were using with fairly good results. Out of desperation we went back to the new Pennfield, more specifically Fibregized Omega, which according to that rep was going to remain unchanged through Nutrena. Within 4 weeks we were seeing ribs, and we then consulted with Cavalor and Purina both of whom didn’t understand why they recommended the Fibregized with it being half the calorie content of what we’d previously been feeding. Cavalor had just about every horse on a different variety of their feed, so we went with Purina, and believe me when I say it was a last resort. I even cringe now when I say that everyone looked the best I’d EVER seen. Things were going swimmingly, until about 8 months in, which is when we started to see issues arising.

We have access to just about every brand under the sun. To date, the only brands we haven’t tried yet are KER and Seminole Wellness, which I have heard great things about.

Again, it’s difficult to break down the amounts of each ingredient per ration, per each of 13 horses. The largest, and the one that is struggling most is a (should be) 1200 lb 17h warmblood currently getting 6 lbs/day. Broken down it is 3 lbs of the base (1 1/2 lbs whole oats, 1 1/2 lbs alfalfa pellets), in addition to 2 cups Renew Gold, 1 cup fresh ground flax, 1 oz v/m, and 2 tbsp spirulina. This gets soaked with an equal amount of alf cubes for the PM meal.

Portions lower in relation to size. Generally speaking, we have smaller horses (15.3-16.2) on 4 lbs/day. Large ponies on 2.5 lbs/day, mediums on 2 lbs/day, and smalls on 1-1.5 lbs/day.[/QUOTE]

You may need to re-evaluate horse weight as it compares to size, my mare is 15.3 hh and lacks some topline, and last I weighed her (on a vets scale) she was 1130lbs. A 17hh warmblood should be somewhere between 1400 & 1500 lbs. He should probably be getting double the food daily.

I also want to note that dietary starch is made up of ESC and WSC meaning “carbs” or more “available energy”. So horses that are getting fed more energy are going to burn more energy (however they can) and may look a little scrawny.

[yourcolorfuladdictio]

[QUOTE=Losgelassenheit;8454326]
The whole food nutritionist said not to go any higher than 3 lbs of the mix per feeding. It was suggested I give another lb of oats at lunch if I really felt the horse needed, but 3 lbs was the absolute max of the mix per AM/PM feeding. The horses get the appropriate weight of hay, but I will say with hay at $16-20/bale, it is difficult to feed it free choice! Hence why we stretched with beet pulp in the past, but when the issues began popping up, we switched to alf cubes. I suppose we could try the beet pulp once again. We have just been leery, since we pulled the feed and beet pulp at the same time, there’s some uncertainty where exactly the issues were stemming from.[/QUOTE]

It sounds like you need to fee more food, whatever it is. If the whole food nutritionist only wants 3lbs per meal, start feeding more hay, if that’s not an option, consider a commercial feed.

[Losgelassenheit]

[QUOTE=yourcolorfuladdiction;8454341]
You may need to re-evaluate horse weight as it compares to size, my mare is 15.3 hh and lacks some topline, and last I weighed her (on a vets scale) she was 1130lbs. A 17hh warmblood should be somewhere between 1400 & 1500 lbs. He should probably be getting double the food daily.[/QUOTE]

The horse is not a “heavy” type, rather tall and leggy with a lot of TB on the dam side. Currently at 1100 lbs right now and vet wants another 100-150 lbs put on. What has them puzzled is the fact that 3 lbs per Am/Pm feeding is what the 1.50m+ jumpers are getting at some of the biggest barns in the area also on the same regimen, and they are competing every week. Why that same amount isn’t sufficient for light to moderately worked hunters is what is troublesome. I always joked I had the isle of misfits, but really…

[Obsidian_Fire]

Is there some reason you can’t just feed regular alfalfa hay?? Rather than cubes. Seems a bale of hay should be cheaper per pound than bagged product.

I know it made a huge difference in my boy and he’s nowhere near on the ceiling, just the opposite.

[JB]

@Losgelassenheit;8454317

Unfortunately, I will have to respectfully disagree on the TC products, at least in our experience. TC Senior was the very first thing we went to once the Pennfield quality slipped, and I have never had to peel such typically calm horses off the ceiling like I did then. Vet and rep said that it was likely a soy sensitivity presenting the issue. Switched to Nutrena and they all came down from the clouds.

Unless the specific feed you used from Nutrena was soy-free, then it wasn’t a soy issue. Regardless, I didn’t say that all horses do well on all TC (or any brand) feeds I said that generally, as a whole, TC is a better brand than Purina, and that is true. That doesn’t mean any given horse will do well on any given TC feed, or can’t do well on any given Purina feed.

Again, it’s difficult to break down the amounts of each ingredient per ration, per each of 13 horses. The largest, and the one that is struggling most is a (should be) 1200 lb 17h warmblood currently getting 6 lbs/day. Broken down it is 3 lbs of the base (1 1/2 lbs whole oats, 1 1/2 lbs alfalfa pellets), in addition to 2 cups Renew Gold, 1 cup fresh ground flax, 1 oz v/m, and 2 tbsp spirulina. This gets soaked with an equal amount of alf cubes for the PM meal.

I too have a hard time believing a 17h horse is only 1200lb. My 16.3 TB was 1320 (on a scale) and my 16.1-2ish leggier TB mare is still 1250lb. My 17h WB is about 1450, though he is a heavier type.

But in the end that doesn’t matter - when a horse needs more food, he needs more food. I still think you are just overall way short on calories and protein and lysine.

Portions lower in relation to size.

Portions have to be relative to the needs, not the size. All 3 of my 16.2 and below horses eat more than my 17h horse, while all 3 of those also weigh less.

@Losgelassenheit;8454352

The horse is not a “heavy” type, rather tall and leggy with a lot of TB on the dam side. Currently at 1100 lbs right now and vet wants another 100-150 lbs put on. What has them puzzled is the fact that 3 lbs per Am/Pm feeding is what the 1.50m+ jumpers are getting at some of the biggest barns in the area also on the same regimen, and they are competing every week. Why that same amount isn’t sufficient for light to moderately worked hunters is what is troublesome. I always joked I had the isle of misfits, but really…

It doesn’t matter what others get, or have gotten. It’s about the metabolism of every individual. I eat almost as much food as my husband who is 6" and 70lb bigger than me

[Palm_Beach]

Soy sensitivity and food allergies are very uncommon in horses, and it’s hard to believe that the OP has an entire barn full. I fed Ultium when it first came out, and to the best of my recollection, alfalfa was the first ingredient. I really dislike that some feed companies will not put the ingredient list online. Since the horses were looking so well on Ultium and Strategy, I’d look for a similar feed. And feed as much hay as they will eat.

[quietann]

This is all very confusing but simple math says these horses are now getting fewer calories than they were. Choices: up the hay (1.5% body weight seems low even for a fairly easy keeper), increase the amount of “whole food” mix and supplement with more protein, go back to commercial feed, but whatever you do they plain need more calories.

It also seems like they did fine on the Purina feed and Ultium, and then suddenly most or all had hives, allergic reactions, etc. That makes me think something had contaminated what they were eating and the Purina wasn’t necessarily the problem. If you switched hay when you undertook the “whole food” diet, it could even have been the old hay! Or something completely unrelated to diet.

To me the “whole food” thing sounds a bit sketchy, and with all the stuff you’re now adding to try to get weight back on, it is starting to depart from a “whole food” diet anyway. What does the nutritionist say? Why does she think your horses are in bad shape now?

[AKB]

There are lots of different Purina feeds. If you think one works better than another for an individual horse, stock several types of Purina. My guys don’t digest plain oats very well. My old guy was underweight on his “custom” diet of oats, alfalfa cubes and lots of other stuff. On Purina Senior, he looks good. My riding horse does best on the McCauley’s balancer pellet mixed into a lb of Purina Ultium.

If your horses look better on Ultium, try supplementing the custom diet with 5lbs per day of Ultium, until they look better. Then, you can experiment with different feeds.

[Palm_Beach]

[QUOTE=quietann;8455357]
This is all very confusing but simple math says these horses are now getting fewer calories than they were. Choices: up the hay (1.5% body weight seems low even for a fairly easy keeper), increase the amount of “whole food” mix and supplement with more protein, go back to commercial feed, but whatever you do they plain need more calories.

It also seems like they did fine on the Purina feed and Ultium, and then suddenly most or all had hives, allergic reactions, etc. That makes me think something had contaminated what they were eating and the Purina wasn’t necessarily the problem. If you switched hay when you undertook the “whole food” diet, it could even have been the old hay! Or something completely unrelated to diet.

To me the “whole food” thing sounds a bit sketchy, and with all the stuff you’re now adding to try to get weight back on, it is starting to depart from a “whole food” diet anyway. What does the nutritionist say? Why does she think your horses are in bad shape now?[/QUOTE]

I tend to agree - I did a little googling on equine allergies and found lots of stuff about insects. Found nothing that related soy as a cause of allergy symptoms.

[Beckham03]

I agree with above. Your horses need more food and your feed is lacking. It has gone from feed to a witches brew with all of the stuff you have to add.

No more then three lbs at a time is coming from is that a horses stomach empties lightening fast, in about fifteen to twenty minutes. They don’t absorb the nutrients of more then that amount at a time, just moves through. This is why a lot of horses suddenly do better with adding a third meal of grain a day.

Increase your hay and find another feed. Nutrena has the safe choice perform and pro force fuel if you want to stay away from purina. Size doesn’t always dictate how much they eat. My moms 15 hand quarter horses eat a lot more grain then my 1300 lb draft cross.

[Texarkana]

I had a similar issue when I took my horses off processed, commercial feed and switched them to a vit/min supp. and minimally processed ingredients/soy-free. On paper, calorie for calorie and even nutrient for nutrient for the major components, the diets looked very similar. Yet my horses’ condition worsened: top lines looked rough, my hard keeper became an even harder keeper, my easy keeper blimped up more, etc. Despite lots of tweaking and adding this and that, I went back to what I was feeding previously after about a year.

What I took away from my experience is something I already knew but had to see for myself: a lot of the “bloom” we see in horses is difficult, if not impossible for some horses, to achieve without the common hard grains and/or over-processed ingredients used in prepackaged feeds. That’s why we began utilizing those ingredients in the first place. Even the most beautiful, high protein alfalfa product is not going to be as balanced and have as complete of an amino acid profile as a serving of soy meal. And corn is one of the most efficient ingredients to pack a lot of useable calories and energy into a horse without a lot of bulk, despite having other negative implications. You can make a similar statement about oats. Then the feed companies fortify the product to already address the majority of the “holes” in the vit/mins so you don’t have to do the trial & error yourself.

I totally agree that a forage only or a minimally processed diet is healthiest for the animal. But for most horses, you can’t feed forage only/minimally processed and still maintain that year-round show hunter look we have come to expect. We created that look in our animals using hard grains and processed feed.

I think the increased sensitivities we are seeing stems from a problem much larger than commercial horse feed, as we are seeing these increased sensitivities and intolerances in nearly every animal species these days. Something in our agricultural or manufacturing process or elsewhere is creating a problem, not the choice of ingredients alone. But that is a debate for another thread!

[Scribbler]

[QUOTE=Losgelassenheit;8454326]
The whole food nutritionist said not to go any higher than 3 lbs of the mix per feeding. It was suggested I give another lb of oats at lunch if I really felt the horse needed, but 3 lbs was the absolute max of the mix per AM/PM feeding. The horses get the appropriate weight of hay, but I will say with hay at $16-20/bale, it is difficult to feed it free choice! Hence why we stretched with beet pulp in the past, but when the issues began popping up, we switched to alf cubes. I suppose we could try the beet pulp once again. We have just been leery, since we pulled the feed and beet pulp at the same time, there’s some uncertainty where exactly the issues were stemming from.[/QUOTE]

The foundation of the “whole foods diet” is as much hay as you need to keep the weight on your horse. If your horse is losing weight, then you need to feed more hay. If (like my horse) you have an easy keeper, then you do need to restrict hay. I don’t think you can do a “whole foods diet” successfully by trying to ration hay as a cost-cutting measure.

Also, it is hard to say what is the appropriate amount of hay without trial and error on an individual horse. My 1100 pound 16 hand muscle-bound stock horse mare maintains her weight nicely on about 15 to 17 pounds of local grass hay a day, so about 1.5 % body weight. Put it up to 20 lbs (closer to 20 %), and she starts to get obese. But friends with big tbds or warmbloods are easily feeding 25 to 30 lbs hay a day. If your horses are underweight, then you need to feed as much hay as they will eat. Do that for a month and see if it helps fix the problem.

Perhaps you could switch to a cheaper grass hay for this extra feed.

I am not sure what a “whole food nutritionist” is. Last year I took a horse nutrition course on Coursera, out of Edinborough University. Standard up to date horse nutrition, supported by research. The text book was Julia Getty’s “Feed Your Horse Like a Horse.” All of this supported the forage-based diet, with minimal concentrates as needed, and tended to recommend feeding components such as oats, beet pulp and alfalfa cubes, rather than commercial products. So I"m not sure how a “whole food nutritionist” would be any different from a regular nutritionist.

As far as the 3 lbs per feeding: as I understand it, there is no upper limit on feeding alfalfa cubes, because they are just alfalfa.

[Palm_Beach]

@Texarkana;8455568

I totally agree that a forage only or a minimally processed diet is healthiest for the animal. But for most horses, you can’t feed forage only/minimally processed and still maintain that year-round show hunter look we have come to expect. We created that look in our animals using hard grains and processed feed.

Tex, what do you mean by “overprocessed?” Unless you are feeding your horse twinkies and ho-hos, I don’t think most feeds fall into the category of “overprocessed.” Some change needs to be made to the ingredients to make the bag of feed uniform in nutritional content and as a way to increase the shelf life. I think equine nutrition has made great stride in the past couple decades and most educated horsemen are feeding forage based healthy diets complemented by a commercial product that is developed by highly educated equine nutritionists to fill in the gaps left by the forage.

By “overprocessed,” I think of an food item that once had some healthful benefits, but has been altered in such a manner that there is little nutritional benefit left. Most bags of feed contain a guaranteed analysis and a list of ingredients, so you know exactly what each pound of feed contains, despite what has been done to the ingredients to formulate the feed.

I make chicken veggie soup, and the ingredients have been frozen, transported, packed, displayed, thawed, refrigerated, chopped and cooked, which is a heck of a lot of processing. And then I freeze some of the soup for later thawing and reheating. But I still feel it’s a very healthy meal. Ice cream - not such a healthy way of getting some protein and calcium. Just trying to make a point about processing.

[Palm_Beach]

@Scribbler;8455919

I am not sure what a “whole food nutritionist” is.

Me either. Like I pointed out above, most educated horsemen are feeding roughage based diets (roughage is a “whole food”) with a concentrate to fill in the gaps, and most concentrate are “whole food” based. Plus, most people feed 3x as much roughage as concentrate.

[Manni01]

sorry that the video is not in English, but somehow this rider gets his year round good look on his horses with pasture, Hay Oats and supplements… I can get as much coat shine and roundness on my horses as I like just with pasture, hay and oats as well. I agree with her

https://www.facebook.com/pferdia/videos/976585435722617/?pnref=story

[Texarkana]

Palm Beach- I don’t think over processed means “little nutrition.” Rather, I think of “over processed” as ingredients that are greatly departed from how they would be encountered naturally.

Feeds composed of a large percentage of wheat middlings would be at the top of the list of what I would consider over processed. But they are used because they have a lot of benefits, namely being an affordable binder with reasonable nutrition. We can create these lower starch feeds with wheat midds, which are “better” for pleasure horses who don’t need the energy from whole grains. But the wheat midds are drastically different than how horses naturally receive their nutrition- they are byproduct after the flour portion is removed, they are refined, etc.

A large number of feeds also contain artificial flavorings, colorings, and preservatives. Artificial doesn’t always equal bad, but those are definitely things that utilize a high degree of processing. We can add a lot of oils and fats to feeds thanks to preservatives and stabilization. Horses tolerate those fats and oils well, but again, it’s quite different from how they would naturally acquire those calories.

Vitamin and mineral fortification is not all created equal. Many of the additives are food based, some come from other “natural” sources, others are synthesized. Fortification allows us to close nutritional gaps, but not necessarily naturally.

And then there is soy- a product that is unusable in its raw form, but can provide extremely high quality protein with some degree of “processing.”

None of these things are “bad” IMHO. Like I said in my earlier post, these are the things that put top lines and dapples on our horses without all that much effort on the part of humans. But we are also seeing what seems to be an increase in unhealthy side effects from these feeds. Personally, I think moderation is usually the best practice- utilize over processed ingredients only when needed, which is what I believe most good horse people try to do anyway.

[JB]

[QUOTE=Manni01;8456802]
sorry that the video is not in English, but somehow this rider gets his year round good look on his horses with pasture, Hay Oats and supplements… I can get as much coat shine and roundness on my horses as I like just with pasture, hay and oats as well. I agree with her

https://www.facebook.com/pferdia/videos/976585435722617/?pnref=story[/QUOTE]

Pick almost any feeding regimen and you can find a horse who does exceptionally well on it.

That doesn’t mean it’s the most economical way to feed, and it doesn’t mean all horses will do well on that diet, and some will do terribly. Bell curve.

Horses evolved eating minimal grains. They nibble on whatever happens to be around at a given time of year if they are in the right place at the right time.

They also didn’t evolve eating high amounts of fat - it’s just not in forage. in significant amounts.

Obviously we place different demands on a horse when we capture him into very non-diverse forage situations and increase his work load, so we can’t always, or even often, feed just forage.

What “supplements” have to be added to a forage/oat (or other grain) diet? Maybe not a lot, maybe a great deal. You end up having to do a lot more micromanaging than you might otherwise. The grass hay is likely to be low in calcium, and grains have a high phos:ca ratio, so you should probably add calcium. The grass is likely to be a bit low in protein, and probably quite low in lysine, and unless you’re feeding 10s of pounds of a grain, you’d probably need to add both.

Then look at the soil - high iron? That forage is going to be low in copper and zinc, and you’re not getting a huge amount from the grains.

I think you get the point - pick a feed and you’ll find 1 and maybe 100 horses doing extremely well on it, and you’ll also find probably 100 horses doing not very well, to very poorly.