The myths about sugars, grass, fertiliser and laminitis

[Sebastian]

Nearly every day I see people asking for advice regarding laminitis and grass. In all of these threads people post what they have been lead to believe, but it is not always correct and I do wonder about where these misconceptions come from. One of my neighbours is a riding instructor and she told me the other day that she is not going to cut her tall and very overgrown fields, because she is worried about laminitis in short grass! I decided not to argue, but there must be a reason why so many believe these "old tales".

Myth: Short grass is stressed, and trying to grow - therefore the sugar levels are far higher than long stalky grass. Leafy and "lush" short grass is the biggest cause of laminitis and must be avoided.
Fact: Actively growing and fertilised grass has the lowest levels of sugars.

Myth: Fertilised grass has higher sugar levels and causes laminitis
Fact: Fertiliser applied when grass is growing lowers the levels of sugars. Nutrient deficiency causes sugars to accumulate.

Myth: Grass should be left to grow long and not mowed. Leafy and "lush" short grass is the biggest cause of laminitis and must be avoided.
Fact: Grass contains the most sugars when it develops seed heads, which contain very high concentrations of sugars. Leafy regrowth has the lowest sugar levels.

Source: all over the place, but this is the best and most concise one I can find

http://www.safergrass.org/pdf/VCNApreprint.pdf

For those too lazy to read the whole thing

Edit: NSC = nonstructural carbohydrates, i.e sugar, starch and fructan

 

[bakewell]

Also, if it's an almost unmanageable problem and you have lami prone ponies... reseed your grass with laminitis mix!

 

[Sebastian]

Also, if it's an almost unmanageable problem and you have lami prone ponies... reseed your grass with laminitis mix!

Indeed. Rye grass free mixes are easily available.

The university also analysed the fructose content of a range of old pasture grass species including Yorkshire Fog, Meadow Fescue, Cocksfoot, Creeping Bent, Red Fescue, as well as Bull Grass (Bromus mellis) and Crested Dogstail. The Ibers grass-seed bank in Mid Wales, donated verified grass-seed from old grass species.
The research project ran from October 2012 until October 2013 and included seasonal comparisons of sugar content together with a two hourly comparisons of five native grass species and two types of perennial rye.

The first set of results received were quite remarkable, indicating the fructose content of both the old and new varieties of perennial rye were high compared to the inferior grass species. The new variety is the highest with a 332mg/g fructose content in comparison to 0.52mg/g in Meadow Fescue. Therefore modern perennial rye-grass, which is the most popular type of grass grown in the UK, has the potential to give the laminitic-prone pony a double whammy of sugar in the form of fructose and also a high ingested fructan level.
Meadow Fescue contains 0.52mg/g fructose, 0.26mg/g glucose and 0.19mg/g sucrose, while the Crested Dogstail results are 0.48, 0.23 and 0.13.

If given the choice of perennial rye over Meadow Fescue the horse will inevitably choose the sweeter variety and over indulge on its sweet sugary content. But though the horse might choose to eat this type of grass because it tastes so sweet, the Meadow Fescue will be a far healthier choice, especially for the native pony.

http://www.farmersguardian.com/home...our-grass-for-a-horse-to-graze?/63000.article

 

[Jaycee]

I've recently covered this in at university and I agree whole heartdly with the OP that there is a tremendous amount of confusion in the best way forward if you have a horse/pony prone to laminitis. We had a guest lecturer come in from a certain barefoot advocate group that claims that grass of any type is the main cause of laminitis which apparently a large percentage of the UK horse population suffer from in one form or another and that we should all keep our horses barefoot and on a track system only feeding them hay - as horses are not designed to eat/process grass! Whilst I appreciate that laminitis is an awful condition for any horse/pony to suffer from I too wish that people would look more into the real facts about grass during its different stages of growth etc., rather than following the current trend

 

[NZJenny]

Not only in regards to grass, but also soaking of hay. Again it seems to be myths v facts and I don't know anyone here in NZ who does it.

 

[OldNag]

Thank you. I understood that short grass was the enemy... turns out not.

 

[PeterNatt]

There are many different opinions about the relationship between short grass and Laminitis so please do not take the above post as gospel.
If you wish to do further reading on the matter then I recommend reading 'Equine Laminitis - Managing pasture to reduce risk' published by the Australian Government Rural Industries Research and Development Corporation (RIRDC) Published in 2010 ISBN 978 1 74254 036 8 ISSN 1440-6845

 

[twiggy2]

It is now thought that very very few cases of laminitis are down to grass and sugars alone and that in nearly every case the laminitis is a SYMPTOM of either cushings, EMS or stress (mental or physical) so managing those will eliminate nearly all cases of lami. obesity is often a cause of EMS (long term cause) so weight needs to be controlled but the thinking that grass per se needs to be restricted is beginning to be doubted. feeding needs to be managed alongside weight by various means not just restricting grass-horses need work (where possible) to keep the body as a whole healthy

 

[Sebastian]

There are many different opinions about the relationship between short grass and Laminitis so please do not take the above post as gospel.
If you wish to do further reading on the matter then I recommend reading 'Equine Laminitis - Managing pasture to reduce risk' published by the Australian Government Rural Industries Research and Development Corporation (RIRDC) Published in 2010 ISBN 978 1 74254 036 8 ISSN 1440-6845

Why don't you post at least a summary of these different opinions, so that we can have an interesting and frank discussion and debate?

You see, opinions on what triggers laminitis change as different research is done, but the misconceptions like the one below about grass and sugars will always be not true, yet it is taken as the gospel on the forum:

Short grass is stressed, and trying to grow - therefore the sugar levels are far higher than long stalky grass

This simply cannot be true, because of how plants work.

 

[Sugar_and_Spice]

I do think some people make horse keeping a lot more difficult than it needs to be. I've no problem with them doing that, as long as their horse is basically ok with whatever routine and management system they use.

My viewpoint is: If people want to worry unduly about laminitis, let them. But I dont. Two of my horses are "at risk" you might say. One which had laminitis with a previous owner and one which a few years ago developed a cresty neck that never goes away even when lean, so IMO a possible metabolic problem. The laminitis case was due purely to suddenly over feeding and lack of work. The cresty neck developed on a horse which had always been fairly slim.

Due to a yard move these two, along with my others, are on decent grazing. Not rye grass, a mix of grass and weeds but a decent amount. It doesn't remotely resemble a starvation paddock. Every summer they get fat. Every winter they slim down. They are worked to a level that suits me, not because I feel I *have* to ride due to their weight. Winter is hard enough work, I'm not interested in stabling in summer too. I detest muzzles. I have no problem if others want to use them but I won't. IME the horse is miserable and the muzzles rub or come off. Soaked hay (more than about half hour) absolutely stinks and the water it comes out of looks disgusting. No, I won't feed that to my horses. Apart from anything else, I have better things to do than lug heavy dripping hay nets around. Anything with dust problems has haylage.

Guess what? My horse keeping routine is easily manageable by me, doesn't give me a headache or create unnecessary work and none of my horses has ever died from it. None has ever had laminitis with me. They are all happy and living a fairly natural life. IMO life is too short for all the worrying and faffing that goes on with a lot of horse owners.

If one of mine ever develops laminitis for no apparent reason (getting into the feed bin, illness, stress etc), I will consider it a symptom of serious metabolic problems and PTS in the animals best interests. Rather than months of painful laminitis recovery followed by a life of muzzles, manky soaked hay and restricted grazing for the poor horse, with riding suddenly becoming a chore that *must* be done.

 

[Auslander]

Yet - on the very same site - a document which states "Do not over graze pastures.The bottom few inches of grass stems often serve as plant carbohydrate reservoir and contain high concentrations of non fibre carbohydrates. Even though intake may be limited on an overgrazed pasture, horses may still ingest too much carbohydrate due to the high carbohydrate concentrations in stem bases.

It's very very subjective, and probably unwise to make emphatic statements, as there really is no final conclusion. I'm no expert, but in my experience, laminitic horses seem to do better on old, long grass. There was a post on this subject recently, where the OP commented that her horses crest became hard on short grass, yet remained normal on longer, older grass. Go figure!

 

[windand rain]

Sugar and Spice that is exactly what I would have written I cannot see the point in worrying and faffing mine have never had laminitis under my regime which is much the same as yours. I did have a pony get it when he was let onto the growing hay by walkers so I thought I would try to help him out by restricting him He hated it became hateful and dangerous so he now lives with the rest does a little work from time to time but I keep them on over grazed fields in summer and let them lose weight in winter works for me too. My theory is that they expend far more energy trying to fill themselves up moving than they get from the grass they are grazing

 

[Palindrome]

I guess it's more complicated than just high or low sugar. I have also heard older grass contains more lignin so this could also affect it's digestion.

 

[fattylumpkin]

I think like Auslander says it's very very subjective. About a billion factors all play into laminitis. I think it's best to educate owners on the universal warning signs that come before a horse develops chronic laminitis (unless caused by a freak incident as sometimes happens) and that way the owners can adjust according to individual needs, rather than try to fit their horses into a cookie cutter lifestyle that advocates all laminitics be treated exactly the same.

 

[DanceswithCows]

Right yeah, short grass contains less energy and it's the stalky seedy stuff that's the problem. That explains why the farming industry decided not to start baling lush ryegrasses at the short and leafy stage and opted to stay with ye olde hay meadows, letting them seed before baling.

 

[Sebastian]

Yet - on the very same site - a document which states "Do not over graze pastures.The bottom few inches of grass stems often serve as plant carbohydrate reservoir and contain high concentrations of non fibre carbohydrates. Even though intake may be limited on an overgrazed pasture, horses may still ingest too much carbohydrate due to the high carbohydrate concentrations in stem bases.

It's very very subjective, and probably unwise to make emphatic statements, as there really is no final conclusion. I'm no expert, but in my experience, laminitic horses seem to do better on old, long grass. There was a post on this subject recently, where the OP commented that her horses crest became hard on short grass, yet remained normal on longer, older grass. Go figure!

If you're referring to the same recent topic that I am thinking of, then another poster in there said that their horses became fat on long grass and are doing better on short grass.

The bottom few inches that you're referring to must be the crown, where grasses store a lot of their reserves.

Horses prefer leafy bits, so they are not likely to eat that low, unless there is nothing left and growing conditions are not favourable and there is little regrowth. You don't want them eating that low anyway, since it's likely to kill the plant. Therefore good management is important to ensure that there is a steady supply of food.

 

[_GG_]

I find posts like this a little concerning if I am honest. We are all guilty of thinking we or something we have read/heard is the right way sometimes, but as has been said by the OP, "opinions change as different research is done". That's it, in a nutshell.

What concerns me when one set of research is hailed as the best/correct etc. is that people can read it, believe it and follow it and that can be to the detriment of their horse(s).

For some horses, long grass works best. For some, short grass works best.

All the research in the world into these kinds of issues will do absolutely nothing to offer practical help to those trying to avoid/manage the issue because the research done on grasses at different stages cannot ever be applied to every horse and their totally individual digestive/metabolic systems.

I agree with the OP that some of the myths are at best silly and at worst, potentially dangerous, but then, so is the information contained in that article because it omits the most important factor...the individual horse.

It's really not, in my opinion, as case of learning about the grasses. That knowledge can be useful, but it has to be more geared to teaching owners how to assess their horses and monitor how they do on different grasses at different lengths and tailor the management of the horse around those findings. To do anything else puts some horses at risk.

 

[pennyturner]

FWIW (and with no scientific evidence behind me, so feel free to contradict), I believe restricting grazing does more harm than good in many cases because it also restricts movement, which is a major contributor to good circulatory health.

Mine aren't restricted, get fat in summer (but not horrifically fat, as they're on grass/weeds, not hard feed), and a bit thin towards the end of the winter. Those in danger of dropping too much condition get a bit of extra hay / haylege / time on the lawn. The older boy gets rugged up, so he can maintain condition on the same forage rations as the rest. They move about lots in winter looking for anything they might have overlooked, as most of their calories still come from the field, not hay. This seems to work, and is less stressful for them and me.

 

[Sebastian]

I find posts like this a little concerning if I am honest. We are all guilty of thinking we or something we have read/heard is the right way sometimes, but as has been said by the OP, "opinions change as different research is done". That's it, in a nutshell.

What concerns me when one set of research is hailed as the best/correct etc. is that people can read it, believe it and follow it and that can be to the detriment of their horse(s).

For some horses, long grass works best. For some, short grass works best.

All the research in the world into these kinds of issues will do absolutely nothing to offer practical help to those trying to avoid/manage the issue because the research done on grasses at different stages cannot ever be applied to every horse and their totally individual digestive/metabolic systems.

I agree with the OP that some of the myths are at best silly and at worst, potentially dangerous, but then, so is the information contained in that article because it omits the most important factor...the individual horse.

It's really not, in my opinion, as case of learning about the grasses. That knowledge can be useful, but it has to be more geared to teaching owners how to assess their horses and monitor how they do on different grasses at different lengths and tailor the management of the horse around those findings. To do anything else puts some horses at risk.

I am not denying anything that you said, however, my points is first and foremost about sugar levels in grasses. Do you not find the fact that this little morsel, "Short grass is stressed, and trying to grow - therefore the sugar levels are far higher than long stalky grass.”, is thrown around as the gospel and fact on the forum frightening? I do, because no matter how much opinions change with new research, how plants grow will not change.

 

[TGM]

I'm not sure I can go with the "let them get fat and if they get laminitis, knock it on the head" approach! But perhaps I have a different outlook as husband is a farrier and I've spoken to so many heartbroken owners who wished they had done things differently before their animals succumbed to laminitis. One of the most common comments is "but X has been always been fat but never had laminitis before so I thought he'd be OK". Unfortunately, being overweight is really a big health risk for equines, and the longer they are overweight, the greater the chance of them developing metabolic problems. It is now known that fat cells can produce a wide range of hormones - if the animal's fat deposits are larger than normal then this can upset the hormone balance and result in the animal becoming insulin resistant, which in turn makes the animal very susceptible to laminitis. So actually being fat long term can trigger the metabolic conditions that can cause laminitis when the animal ingests too many non-structural carbohydrates (ie sugar and starch).

There are different ways to manage lami prone animals and they don't all have to include muzzling and soaking hay - you have to make the best choice for the individual concerned. I have a pony who easily puts on weight, so she gets a separate strip of grazing where she has to wander around a lot to eat. And yes, sometimes I do have to ride her more than I always want to because I want to keep her fit and sometimes it is hard work to keep horses healthy and sound - personally I want to avoid a situation where I have to have my pony put down because I can't be bothered to put the work in!


I posted this quote from a vet site in a previous thread on the subject, unfortunately the original article I linked to has now gone, but I think the quote explains what the theory quite well:

"Obesity, as a direct result of excessive calorie intake, is the primary cause of insulin resistance in horses (as with people). It is now known that fat cells can produce a wide range of hormones and inflammatory mediators. These hormones down-regulate the sensitivity of tissues to insulin, which is a normal body function. However, if they are produced by larger than normal deposits of fat, their down-regulatory action is too much for the body to cope with and insulin resistance occurs. The excessive production of inflammatory mediators by the fat tissue also leads to a constant state of low grade inflammation. "

 

[_GG_]

I am not denying anything that you said, however, my points is first and foremost about sugar levels in grasses. Do you not find the fact that this little morsel, "Short grass is stressed, and trying to grow - therefore the sugar levels are far higher than long stalky grass.”, is thrown around as the gospel and fact on the forum frightening? I do, because no matter how much opinions change with new research, how plants grow will not change.

I do find it worrying. That's why I think people should be encouraged to learn about their particular horse as well as learning about grasses.

 

[mystiandsunny]

In my direct experience: fertilized, lush rye grass that is growing on rich soil is the most likely to trigger laminitis. That aside, the most dangerous weather conditions are rain after a period of sunny weather. Those conditions affect my EPSM horse and my lami prone one. Short grass is preferred by the horses (I think because of greater exposure to sunlight per cm of stem but not sure!) and long, woody grass does not cause problems. Poorer soil is always better, especially well drained soil.

On a well drained, sloping hillside with poor soil and grass that is allowed to grow long and woody, I can keep my lami prone mare and her EPSM companion out 24/7 with grazing muzzles. Works for us.

 

[Sebastian]

I'm not sure I can go with the "let them get fat and if they get laminitis, knock it on the head" approach!

Who is advocating that approach?

As you said, excessive calorie intake is a problem and we completely agree on that. The misconception that I am trying to address is, "Short grass is stressed, and trying to grow - therefore the sugar levels are far higher than long stalky grass". Short grass is not stressed if it is growing. Growing grass is the opposite of stressed grass, even though many people think it means the same thing.

 

[Sebastian]

In my direct experience: fertilized, lush rye grass that is growing on rich soil is the most likely to trigger laminitis. That aside, the most dangerous weather conditions are rain after a period of sunny weather. Those conditions affect my EPSM horse and my lami prone one. Short grass is preferred by the horses (I think because of greater exposure to sunlight per cm of stem but not sure!) and long, woody grass does not cause problems. Poorer soil is always better, especially well drained soil.

On a well drained, sloping hillside with poor soil and grass that is allowed to grow long and woody, I can keep my lami prone mare and her EPSM companion out 24/7 with grazing muzzles. Works for us.

Rye grass is most likely to cause problems, regardless of what stage of growth it is at. Fertilised and actively growing rye grass will have less "sugar" than dormant/stressed rye grass. How "sugar" intake affects a particular horse is another discussion and I agree with _GG_'s views on that point.

 

[PolarSkye]

To be honest, this debate is as circular as all those about whether to rug, clip, stable, etc. Yes, the basic physiology of grasses remains the same . . . but, horses are individuals. Put simply, it's dangerous to blindly follow science without taking into account the many factors that contribute to how the individual should be managed: breed, age, general health, location (Siberia or Hawaii), amount and type of work, quality/nature of grazing, amount of time stabled, etc.

Two other factors which need to be taken into account: knowledge of owner/carer/manager, and "relativity" - by which I mean what are the benchmarks . . . one person's "medium" work level, is often not the same as someone else's. I know plenty of owners who would say their horses were in medium work who would be dead wrong . . . and the scary thing is that they manage their horses to that benchmark - in terms of feeding, rugging, stabling, physio/bodywork, etc.

I'm not sure if the above makes any sense - it did in my head .

P

 

[_GG_]

To be honest, this debate is as circular as all those about whether to rug, clip, stable, etc. Yes, the basic physiology of grasses remains the same . . . but, horses are individuals. Put simply, it's dangerous to blindly follow science without taking into account the many factors that contribute to how the individual should be managed: breed, age, general health, location (Siberia or Hawaii), amount and type of work, quality/nature of grazing, amount of time stabled, etc.

Two other factors which need to be taken into account: knowledge of owner/carer/manager, and "relativity" - by which I mean what are the benchmarks . . . one person's "medium" work level, is often not the same as someone else's. I know plenty of owners who would say their horses were in medium work who would be dead wrong . . . and the scary thing is that they manage their horses to that benchmark - in terms of feeding, rugging, stabling, physio/bodywork, etc.

I'm not sure if the above makes any sense - it did in my head .

P

Perfect sense to me

 

[Sebastian]

To be honest, this debate is as circular as all those about whether to rug, clip, stable, etc. Yes, the basic physiology of grasses remains the same . . . but, horses are individuals. Put simply, it's dangerous to blindly follow science without taking into account the many factors that contribute to how the individual should be managed: breed, age, general health, location (Siberia or Hawaii), amount and type of work, quality/nature of grazing, amount of time stabled, etc.

Two other factors which need to be taken into account: knowledge of owner/carer/manager, and "relativity" - by which I mean what are the benchmarks . . . one person's "medium" work level, is often not the same as someone else's. I know plenty of owners who would say their horses were in medium work who would be dead wrong . . . and the scary thing is that they manage their horses to that benchmark - in terms of feeding, rugging, stabling, physio/bodywork, etc.

I'm not sure if the above makes any sense - it did in my head .

P

I most agree with you and it does make a lot of sense, but personally, I prefer facts from repeatable experiments and testing using a scientific method, than going by anecdotal evidence and advice given by people when we do not know the random and uncontrolled factors, which is exactly what you mentioned. You can add others into it as well, like amount of shade in the paddocks and so forth.

 

[_GG_]

I most agree with you and it does make a lot of sense, but personally, I prefer facts from repeatable experiments and testing using a scientific method, than going by anecdotal evidence and advice given by people when we do not know the random and uncontrolled factors, which is exactly what you mentioned. You can add others into it as well, like amount of shade in the paddocks and so forth.

That's just the point. I too err towards science in almost all scenarios, but not where one of the factors is a living thing. I think that scientific research is incredibly important and should absolutely be taken into advantage. I just don't think it should be followed to the t without consideration of the other factors.

 

[PolarSkye]

I most agree with you and it does make a lot of sense, but personally, I prefer facts from repeatable experiments and testing using a scientific method, than going by anecdotal evidence and advice given by people when we do not know the random and uncontrolled factors, which is exactly what you mentioned. You can add others into it as well, like amount of shade in the paddocks and so forth.

I prefer facts too, not to mention repeatable experiments - however once you leave the laboratory and start applying the science across the broader horsey world, you lose the rigour - which is why the science needs to be tempered with variables - which brings us back to individuality - of horses, owners, and all the factors mentioned above.

P

 

[cobgoblin]

For me the really interesting thing to come out of this thread is the relative difference in the sugar content of different grasses. I'm sure we all knew that ryegrass isn't the best for horses, but I'm astounded at how much more sugar it contains
Does anyone know whether laminitis is as common in countries where old natural pastures still remain in any quantity? I ask because I have an elderly friend who was born in Bavaria between the two world wars, she has always been surprised at the prevalence of laminitis in the uk. She says that when she was a child everyone's ponies used to eat as much grass as they liked and were enormously fat in the summer, in the winter they were fed hay and oats, but laminitis was unheard of unless a pony broke into the feed bin!