FeedXL goes above and beyond Nutrient Requirement of Horses (NRC)
FeedXL is a combination of NRC nutrient requirements and customised nutrient requirements based on our own research as well as information taken from the most recent and comprehensive text on equine nutrition, ‘Equine Applied and Clinical Nutrition’1
The Short Story
In brief, digestible energy is always determined as per NRC requirements as we could find no evidence to support adjusting it from the levels determined by NRC. In practice, DE requirement for an individual horse is an estimate. Many factors, including climate, level of natural exercise the horse undertakes and the actual diet and how efficiently or inefficiently it is digested will impact a horse’s actual DE requirement.
The Long Story
Crude protein and lysine are set as per NRC for pregnant & lactating mares, spelling and lightly worked horses and growing horses. But we slightly elevate both crude protein and lysine requirements for horses in moderate to heavy work as well as breeding stallions. We are perhaps a little conservative on protein and lysine but also see good evidence in practice to show that when crude protein and lysine requirements are met using high quality protein sources we are able to support pregnancy and lactation without the loss of muscle in broodmares and we get well grown and developed yearlings and 2 year olds, allowing us to conclude that the NRC requirements where used are adequate… provided the underlying diet is well formulated.
Calcium and phosphorus requirements are elevated across the board above NRC requirements and are closely aligned with the requirements set by Prof Pat Harris1
Copper, zinc and manganese are similarly elevated across the board from NRC with the exception of spelling horses that are calculated as per NRC requirements. The largest elevations are seen in the growing horse and pregnant mare diets in an attempt to reduce the risk of developmental orthopaedic diseases like OCD.
Selenium is elevated above the NRC requirement. The NRC state that their recommended daily intake for selenium is the level required to prevent classic deficiency symptoms and that more is potentially useful to maintain more optimal immune function. Thus FeedXL uses an elevated selenium requirement that aligns closely with Geor et al1.
FeedXL follows the NRC recommended daily intake for iodine for all classes of horses.
Iron follows the NRC recommended daily intakes for all horses except those in moderate, heavy and very heavy work where requirement is elevated to account for iron lost in sweat.
Sodium, chloride and magnesium largely follow the NRC requirements. There are some small variations, with growing horses sodium requirements being slightly higher than NRC and magnesium being higher for pregnant and lactating mares.
Potassium requirements are higher than NRC across the board but this was more from a practical ‘user interpretation’ standpoint in FeedXL. Because forages are so high in potassium, if we used the NRC recommended daily intake for potassium, we would see several hundred times the required amount in diets and this was worrying for our FeedXL users. Because potassium is so safe we have elevated the requirement to reduce the amount of worry for people analysing diets. In over 20 years of formulating diets we have not seen a potassium deficiency, even with our elevated requirement, nor is it necessary in all but very unusual cases to add potassium to diets.
Very little is actually known about vitamin A requirements in horses. In FeedXL, Vitamin A requirements are guided by Geor et al with Vitamin A elevated across the board from NRC requirements. Likewise vitamin E levels follow a similar trend.
Vitamins D, B1 and B2 are as per NRC requirements.
Vitamins B5, B6, niacin and folic acid are calculated based on small amounts of research in horses as well as humans, rats and pigs. The recommendations for these vitamins are relatively conservative because there are no established NRC equine requirements, but they serve to ensure diets are meeting what we estimate to be the likely dietary requirement for horses.
Geor, R.J., M. Coenen, and P. Harris, Equine Applied and Clinical Nutrition: Health, Welfare and Performance. 2013: Elsevier Health Sciences.
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Let’s discuss a common scenario – you want to maintain good bodyweight for your horse, so you’re feeding only enough to do just that. You’ve done your research and found feeds that you like and your horse is maintaining a healthy weight. You’re doing everything right, right?
Wrong. Did you know that even with high quality feeds, if you aren’t feeding the full recommended serving, your horse could be suffering from a vitamin or mineral deficiency?
Even if the amount being fed is enough to maintain your horse’s weight, if it isn’t enough to cover your horse’s vitamin and mineral requirements, this will eventually result in hoof, joint, performance, immune function and general health issues. The problem is that you won’t see that until something big happens.
Maintain your horse’s weight the healthy way
Watch the video below as we walk through an example diet. This horse, Ash, has a lovely diet, except it doesn’t meet all of his nutritional requirements. With a few simple changes, FeedXL shows how to correctly balance the diet to meet all of his needs, including maintaining his weight.
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Is your horse getting everything he needs to thrive?
Many of the best horse owners could be missing hidden dietary deficiencies in their horses, simply because they aren’t calculating to see if their horse’s diets are balanced or not.
Looking at the outside of our horses, most horse owners are pretty good at knowing how much feed our horses need. We can see weight change which gives us a visual clue that the horse is not being fed enough (resulting in weight loss), or too much (resulting in weight gain).
What we can’t see are the vitamin and mineral deficiencies. And the problem is, these hidden deficiencies often won’t show up as something we can see until they result in disaster – hooves falling apart, joints breaking down, an immune system so compromised that it can’t mount an effective immune response to a simple disease challenge.
Here is a classic example of a diet where the horse’s owner has done a truly great job in putting together a forage-based diet with just enough of a single feed to maintain excellent condition. But the small amount of feed is not enough to meet the horse’s basic vitamin and mineral requirements and can result in a dietary deficiency that could cause long term problems for this horse.
Check the video out as we walk you through Lacey’s diet, which perfectly demonstrates what is happening in so many horse’s diets.
The good news is, with just a little bit of time spent in FeedXL and the addition of a single supplement, Lacey’s diet can be fully balanced to keep her healthy and happy in the long term!
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When using products commonly soaked prior to feeding (things like beet pulp, copra meal, high fibre pellets and hay that is soaked to remove sugars), always enter them into your FeedXL rations as their dry weight.
The Two Main Reasons to Always Enter Dry Weight:
When you add water it increases the weight of what you are feeding, but it doesn’t add any nutrients itself.For example, if you are feeding 500 grams of beet pulp which contains 5.9 MJ of digestible energy, then this is the amount of energy we want to be taken into account in the diet. If you add 1.5 litres of water to that 500 grams of beet pulp and feed a total of 2 kilograms of WET beet and enter THIS weight into FeedXL, FeedXL will not realise the water has been added and think you are feeding 2 kilograms of dry beet and therefore put 23.6 MJ of energy into the diet. Big difference! And a huge overestimation of the actual energy being fed.
FeedXL also won’t be able to accurately estimate pasture intake if you enter the wet weight of the feeds because FeedXL won’t know that a portion of your feeds are water and will therefore count that water weight as feed weight and will reduce pasture intake accordingly.
You might now be wondering why we don’t then allow you to specify you are feeding the product wet – the answer is simply because FeedXL can’t possibly know how wet you feed your soaked ingredients and you will likely make them a bit wetter or a bit drier each time you feed, so it is most accurate to just have everything entered in its dry form.
So, always remember that when you’re weighing your horse’s feeds, enter amounts into FeedXL in their dry form in order to accurately develop rations for your horse. Then go ahead and add as much or as little water as you like!
Do you have a question or comment? Do you need help with feeding?
We would love to welcome you to our FeedXL Horse Nutrition Facebook Group. Ask questions and have them answered by PhD and Masters qualified equine nutritionists and spend time with like-minded horse owners. It’s free!
Are you ready to start using FeedXL to build a balanced diet for your horse? Entering accurate information on your horse and what you are actually feeding is so important for making sure the diets you get out are accurate. Here are the most important things you need to get right!
Bodyweight
Your horse’s bodyweight is the most important piece of information used to calculate your horse’s daily nutrient requirements.
If it is too heavy, nutrient requirements will be overestimated and you will end up over feeding your horse.
If it is too light, nutrient requirements will be underestimated and you may end up under feeding your horse.
The best way to get a bodyweight for your horse is to weigh him. BUT, when weigh scales are not available, we recommend using our bodyweight calculator.
The bodyweight calculator lets you enter the girth and length measurements of your horse and it calculates the bodyweight for you. We highly recommend that you measure your horse’s girth and length, and whenever possible weigh your horse on a set of scales to calibrate or confirm the girth and length weight measurement method. All you have to do is measure your horse as shown hereand then enter the measurements into FeedXL and we calculate the weight for you. Easy!
You can change the horse’s weight after it has been saved by using the Retrieve Horse button and editing the weight. It is important to check and update your horse’s weight regularly and update the diet if the weight has changed.
Tip: To get to this screen, click the ‘Bodyweight Calculator’ button when entering your horse’s details.
Weight of Hay
It is really easy to over or underestimate the weight of hay you are feeding. If your horse has access to Free Choice hay, enter it here at the ‘Free Choice Forages’ step.
If you feed hay in specific amounts each day, get yourself a set of fish or luggage scales and weigh each type of hay you feed so you can enter the weight accurately. This can then be entered in the ‘Prepare Diet’ step where you will add any other items fed by weight.
Weight of Feeds and Supplements
It’s also very difficult to accurately estimate the weight of feeds and supplements you might use as their weight per volume is so different depending on the ingredient. Get yourself a set of $20 kitchen scales and weigh everything you feed so you can get a really accurate assessment of your horse’s diet.
The secret to how to enter your horse’s diet info into FeedXL is simple: entering accurate information means the assessment of your horse’s current diet will be accurate. And of course, when you make adjustments and create your preferred diet, you should also weigh accurate amounts when you are feeding to make sure what you are feeding is the right amount!
Do you have a question or comment? Do you need help with feeding?
We would love to welcome you to our FeedXL Horse Nutrition Facebook Group. Ask questions and have them answered by PhD and Masters qualified equine nutritionists and spend time with like-minded horse owners. It’s free!
A: No. And in fact, it would be impossible to create a diet that had every nutrient in FeedXL exactly at 100% of your horse’s requirements.
Q. So if not 100%, where should the nutrient levels be sitting? And what is normal? Because some of the amounts on this graph look really high?! Isn’t that dangerous???
A. Good question! And the answer is it depends on the nutrient. Forages, for example, contain high levels of some nutrients like iron and potassium. Because diets often have lots of forage, these nutrients will almost always be high in the diet.
BUT that doesn’t mean it is dangerous. In fact, if you push a nutrient to a dangerous level, FeedXL will warn you – the bar for that nutrient will turn red, like this, to warn you that the nutrient is now at its ‘upper safe limit’ and needs to be reduced.
Q. OK, that’s good! So, I know if I get a nutrient WAY too high FeedXL will warn me. BUT I still don’t know what is normal for all of the nutrients. Where should I expect to see them?
A. Yep, let’s walk you through them! We’ll use this graph and go through each nutrient.
Digestible Energy
This should sit, for most horses, somewhere between 90% and 105% of requirements. SOME horses have a lower or higher need for digestible energy (calories) so you may see the odd horse sitting below 90% or above 105%.
BUT, if you do enter a horse and the Digestible Energy is low or high and this does not correspond accurately with what you are seeing in your actual horse (meaning if the Digestible Energy is low in the diet you enter into FeedXL, normally you would expect to see weight loss. If it is high, normally you would expect to see weight gain) you MAY need to double check the information for this nutrient that you have entered into FeedXL as this is a small red flag that something has not been entered right.
For example, if you have entered bodyweight that is too high, the Digestible Energy level will be low and vice versa. Or if you haven’t weighed your feeds and hay or classified your pasture correctly and you have entered amounts or qualities that are too low, then Digestible Energy will appear low and vice versa.
Quick Tip: If Digestible Energy in your horse’s diet is below 90% or above 105%, check that you have entered your horse’s bodyweight and weights of feed and forages correctly. You can also refer to this article on How to Check if What You’ve Entered into FeedXL is Correct which can guide you a bit further on getting it right.
Crude Protein
The Crude Protein level in the diet should always be at or above 100% when entering this nutrient into FeedXL. And it is best to try to keep it less than 200%. For performance horses that are stabled and in work try to keep Crude Protein below 160% if you can… it is not always possible!
Depending on your forages, you may see Crude Protein go very high (well above 200%). Is this an issue? Generally it’s not, but there are some situations (like very hot, humid climates or when a horse is stabled) that it is not ideal. Sometimes, if it is your pasture for example that is high in protein, there is not a lot you can do about it. If the horse is stabled and fed hay, you should try to switch some of the higher protein forage (e.g. alfalfa/lucerne) for a lower protein forage (like a meadow/grass hay), to bring the overall amount of Crude Protein in the diet down.
Lysine is your indicator of protein quality (you can read about Protein Quality here https://feedxl.com/30-understanding-protein-quality/). When entering this nutrient into FeedXL, Lysine should sit between 100% and 150%. If it is lower, it indicates your protein quality is low and your horse will struggle to do things like build muscle or make milk. In fact, when lysine is low in a diet you will likely see your horse losing muscle over his topline… it’s an important nutrient to get right in the diet.
Lysine may get quite high in some diets depending on the amount and source of crude protein. But if you follow the guidelines above for Crude Protein, you will find Lysine levels will adjust accordingly.
Calcium
Calcium should be at or above 100% in the diet and it’s good to keep it below 200%. Ideally, below 150% but depending on the feeds and forages being used, it is not always possible to achieve this. The amount in the diet shown here is lovely, more than the horse needs but well below 200%.
It is important with calcium to also check the calcium to phosphorus ratio in the diet (look in the Nutrient Table) to make sure it is within the right limits with phosphorus. And if you like to use the extra ratios, you can also check its ratio with magnesium, which as a guide, should be 3: 1 or less.
Phosphorus
Phosphorus should be at or above 90% and ideally below 150%. You may see some diets with high phosphorus ingredients like Rice Bran pushing phosphorus higher than this. If it is above 150%, be sure to check the calcium to phosphorus ratio on the nutrient table to make sure this is still balanced (there MUST be more calcium in a diet than phosphorus).
NOTE: You cannot calculate the diet’s calcium to phosphorus ratio off the numbers on the graph. It is always best to read the ratio off the nutrient table. FeedXL will warn you if the calcium to phosphorus ratio is too high or low!
Copper, Zinc, Selenium and Iodine
We group these trace minerals together because they all share the same characteristic that they are almost ALWAYS at low levels in forages. Which means they are nearly always deficient in diets before you add fortified feeds or supplements.
This means that you can aim to keep these nutrients as close to 100% as possible. The diet shown here uses a single vitamin/mineral supplement to meet trace mineral requirements.
This is what the diet looked like before I added the supplement:
You can see these 4 minerals are all low. I used the Supplement Finder (i.e. the BIG PINK BUTTON on the Results Step) to find a supplement that would fill all of these gaps. Ideally what you want to see when you use a single supplement is that at least one of these minerals is sitting very close to 100%. That is your green flag that you have the amount of supplement at the right level. Increasing the amount from this point is just a waste as all requirements are already met, while reducing it would mean the amount of this nutrient (selenium in this example, which is sitting at 101%) would no longer be meeting requirements.
The same rules also apply when using a fortified feed to meet vitamin and mineral requirements. Except that you also have to consider the amount of Digestible Energy the feed is adding.
This is not a super simple concept, so if you are confused, please keep asking questions, as the more you understand this, the easier it will be to use FeedXL effectively.
Quick tip: You can try to keep copper, zinc, selenium and iodine as close to 100% of requirements as possible. If these nutrients are above 200%, I would be trying to find ways to reduce them. This may mean switching feeds or supplements!
Manganese, Iron, Magnesium and Potassium
These minerals are almost always HIGH in forages. Therefore, you will almost always see them sitting well above your horse’s 100% level in the diet. Is this a concern? No. There are always exceptions, but for the majority of horses, no, it is not a problem when these minerals are well above 200%.
Thing is, because these nutrients are rich in forages, it is almost impossible to get them closer to the 100% mark. You could reduce the amount of forage, but the downside of that (higher risk of ulcers, boredom, compromised hindgut health, higher risk of dehydration and colic) far outweighs any potential upside. In fact unless levels in the forage are extreme and the bar for a nutrient goes red, there really is no upside to reducing forage.
If you are concerned, because sometimes it does look scary, just read the notes in the FeedXL Nutrient Table or the hover box on the graph to put your mind at ease. For example, Iron in this diet is at 331%. Which seems really high! But, the notes will tell you:
“While this horse’s iron is higher than it needs to be it is still within the safe range. His upper safe level for iron is 6,019 mg or 943% of his RDI”
So, the upper safe limit is 943%. This diet is a long way off that, so even though 331% seems high, it is very much within the safe zone!
For those of you who like to look at the iron: copper: zinc: manganese ratio, it is calculated for you in the Nutrient Table.
Sodium and Chloride
Sodium and chloride are the two components of ordinary table salt. So together they can make a feed taste very salty. If a feed gets too salty your horse may stop eating it, because it simply doesn’t taste good (and can’t blame them!). So, I like to keep sodium as close to 100% as I can, by adjusting the amount of salt in the diet.
There are a few exceptions. If your horse is in a very hot and humid climate you may need to feed more (more info here https://feedxl.com/40-electrolytes/) or if you are trying to increase water intake for some reason, more salt is useful. But under normal conditions, sitting sodium at or very close to 100% is best. BUT also, always make sure your horse has access to free choice salt!
Chloride is a bit of a lucky dip and its final level in a diet will depend on the amount in your forages. I don’t pay too much attention to where chloride ends up. In fact I don’t think I have ever had to adjust a diet specifically to change the level of chloride (for any dairy nutritionists reading this, it does play a big role in DCAD, but that is another story for another day 🙂 ).
Vitamin A
If you are obsessive about getting nutrients close to 100% in your FeedXL nutrient chart, Vitamin A is your friend! You will notice it is nearly always sitting on 100% of requirements. Why?
Well, in forage, the ‘vitamin A’ content is not active vitamin A. It is in the form of Beta Carotene which can be converted to vitamin A IF your horse needs vitamin A. So, they will only convert it if they need it.
FeedXL models this physiology and takes into account ALL vitamin A from feeds and supplements as this will be an active form of vitamin A (which can become toxic, so we need to count all of it). But then FeedXL will only convert vitamin A to active form from forages IF your horse needs more vitamin A.
For example, if your feed + supplement provides 80% of your horse’s requirement for vitamin A, FeedXL will just top up the remaining 20% of vitamin A from forages to meet 100% of your horse’s requirement. Which is why Vitamin A is very often sitting right on 100%.
If your feeds and supplements provide more than 100% of your horse’s requirement for vitamin A you will see it above 100%. This is OK, as long as it is within safe limits (though personally I would keep it under 200%).
Vitamin E, Vitamin B1 and Folic Acid
These three are grouped together because they will often be low in diets before you add some kind of fortified feed or supplement. And they are all relatively expensive nutrients, so for the sake of cost, you want to make sure your horse’s requirement is met, but if levels of these vitamins go above 200%, you may be paying a lot for nutrients your horse doesn’t really need. Keep them between 100% and 200% if you can. In the case of this diet, the supplement used was rich in Folic Acid, so it has tipped above 200%, but the E and B1 are at nice levels so nothing to worry about with the Folic Acid in this case.
Quick Tip: Keeping these nutrients below 200% will make sure the diet is not excessively expensive!
Vitamin B2, Niacin, Vitamin B5 and Vitamin B6
This crew are all grouped together because forage is OFTEN high in these vitamins so you will normally see levels WELL ABOVE 100% for all of these vitamins. Is that something you should be concerned about? Not at all. In fact all of these except vitamin B6 are considered non-toxic. And the vitamin B6 upper safe level is very high (in this diet the upper safe limit is 5000%!!).
Quick Tip: You can ignore these nutrients as long as they are ‘green’. They will almost always be well above 100%, but it is nothing to be concerned about!
I hope that helps you a little to read the graph and to put your mind at ease about what is and is not normal for certain nutrients. If you have questions, please be sure to ask in the FeedXL Horse Nutrition Forum on Facebook!! We truly want you to know as much as you can about what FeedXL is showing you!
Do you have a question or comment? Do you need help with feeding?
We would love to welcome you to our FeedXL Horse Nutrition Facebook Group. Ask questions and have them answered by PhD and Masters qualified equine nutritionists and spend time with like-minded horse owners. It’s free!
Extreme weather can increase the trend for people to add large amounts of salt to their horse’s daily feeds, despite actual requirements or what may be coming from the rest of their diet. While horses need sodium or chloride to continue to sweat, it’s important to remember that commonplace blanket recommendations like “add 10g of salt per 100kg of bodyweight” don’t take into account a horse’s specific condition.
Take this horse’s diet for example, shown in the graph below. If we add 10g/100kg of bodyweight to his diet, his sodium intake is well over 200% of what he needs. In extreme heat conditions, this may well be accurate, but once it cools off, this is way more sodium than he needs.
What does excessive salt do to the bacteria in their gut? Salt is, after all, one of the best-known and most widely used anti-bacterial agents in the world.
A paper published in ‘Nature’ (one of the most reputable journals in the world) showed that in both humans and mice, adding more salt than normal to a diet affected the gut bacterial populations – in some cases even entirely wiping out certain strains of bacteria. The researchers were then able to link those shifts in gut bacteria to high blood pressure, which may help to explain the link between high salt diets and hypertension.
For horses, feeding excessive salt is unlikely to have any benefit and may be negatively affecting the good bacteria in your horse’s gut. When using FeedXL, be sure to meet but not exceed your horse’s requirement for sodium with salt that is added to the diet. Then leave free choice salt out so that they can top up any extra requirements they may have.
Do you have a question or comment? Do you need help with feeding?
We would love to welcome you to our FeedXL Horse Nutrition Facebook Group. Ask questions and have them answered by PhD and Masters qualified equine nutritionists and spend time with like-minded horse owners. It’s free!
Grains should be fed at a minimum, as high-grain diets can have many complications, including colic, hindgut problems, stomach ulcers, excitable or “hot” behavior, and more. Instead, look to balance your horse’s diet with quality forage and healthy sources of protein and fat. Ration balancers or concentrates are another good option. FeedXL can help you build your horse’s diet without feeding excessive amounts of grain.
When feeding grain to horses, it’s best to feed in small, frequent meals. It’s recommended to feed no more than 1kg/meal for a 500kg horse (or 2lbs/meal for a 1000lb horse). Because horses have only one stomach and their digestive system was designed to be grazing constantly, feeding in these small, regular intervals serves to mimic this and to avoid an empty stomach full of acid, which can cause ulcers.
Sometimes feeding more gives your horse less
When we exceed about 2.5 to 3% of a horse’s bodyweight in feed per day (so 12.5 to 15 kg for a 500 kg horse) the feed starts to move really quickly through the gut. Problem is, digestion, and particularly fiber digestion takes time. Fiber is digested via fermentation in the hindgut (more on how that works here) and fiber fermentation is a slow process. So feed needs to just have the time to hang about in the hindgut for a fair while (like 24 to 48 hours).
When we feed too much, feed gets pushed through the gut really quickly (essentially as it comes in the front end it gets shoved out the back) and it will only be partially digested… so you may be feeding a lot, but your horse doesn’t have full opportunity to digest it.
Think about it like this…
If you had a pool noodle, one of the ones with a hole in it, and were told to keep it perfectly flat/horizontal and then push a small bucket of marbles through the noodle one by one… you would poke them in one end (and assuming it’s flat so they don’t just roll out) they would only start coming out the other end once the entire noodle was full and as you pushed one in, one should come out… make sense?
Now suppose you were told to take 10 minutes to put all of the marbles through the noodle… you would need to take your time in poking one in so they didn’t come out too fast.
Now, if you had a bucket of marbles 3 times the size of the original bucket and told to push all of these through the pool noodle in 10 minutes you would have to do it three times as fast to get them all done in time. When you feed too much this is what happens, feed goes in one end and comes out the other too fast and only partially digested.
In a lot of cases, less is more!
Feeding less gives the feed time to sit around and move slowly through the gut, allowing it to be fully digested. Not much sense making expensive manure right?!
Take a look at your feed program and feed amounts and see if this might apply… often when we try to push for weight gain we get stuck in this trap of feeding too much and it doesn’t seem logical to feed less to get more weight gain.
Do you have a question or comment? Do you need help with feeding?
We would love to welcome you to our FeedXL Horse Nutrition Facebook Group. Ask questions and have them answered by PhD and Masters qualified equine nutritionists and spend time with like-minded horse owners. It’s free!
