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Feeding Chart
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Product Overview

Ideal nutrition for horses fed alfalfa

Mega-Mag™ (Pellet) is a well-balanced multi-vitamin and mineral supplement formulated to coincide with current NRC (National Research Council) recommended daily requirements, to accommodate feeding programs consisting of alfalfa hay/grain based diets. The addition of live, stabilized direct-fed microbials, live cell yeast culture, and amino-acid content, sourced from alfalfa meal, rice bran, and soybean meal makes Mega-Mag™ an excellent choice to support growth, stamina, conditioning and maximum performance for all disciplines.

Note: To accommodate feeding programs consisting of grass-type hays (timothy, coastal, Bermuda, native grass)/grain, choose Mega-Cell™.

  • Comprehensive selection of vitamins & minerals plus probiotics, yeast & amino acids
  • Formulated to coincide with current NRC (National Research Council) recommended daily requirements

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Key Ingredients


Supplement Facts

Ingredient Name Amount Per Serving
Ingredient Name Amount Per Pound

Ingredient Details


Weight Recommended Amount Loading Amount

How the Ingredients Work


Supporting Success

Supercharge Your Supplements

  • Simplify with SmartPaks | Consistent, Custom, Convenient
    We take the guesswork out of serving sizes, ensuring your horse gets the right amount, every time. SmartPaks have airtight seals to ensure that your horse always has the freshest supplements available. Your horse is unique and his supplements should be too. Choose from over 230 supplements to get everything he needs, nothing he doesn't. We print your horse's name on every Pak so there are no mix-ups, making feeding time fast, accurate and easy! Unlike most buckets, SmartPaks are made from recycled plastic and can be recycled again! We'll send your SmartPaks on time so you never run out, with total flexibility and no commitment. Plus all SmartPaks over $40 receive free ground shipping.


The reviews provided on this website represent the experience of the individual posting the review. We do not adopt, edit, or endorse any of the submissions posted within the reviews section. Rather, the reviews are part of an online community of animal owners that desire to share their particular experience with other individuals. These reviews are not a substitute for discussing the health of your animal with a veterinarian.

SmartPak customers are some of the most conscientious animal owners around. We encourage you to share your experience with the products we sell to help fellow customers to make informed choices for their animals. We do not edit these reviews in any way - they are direct customer-to-customer communication. We do monitor reviews for positive and negative feedback, and use this feedback to improve our selection as well as sharing feedback with product manufacturers to help them improve their products. Please note that we recommend consulting your vet with serious health issues.

Mega-Mag™ is rated 4.7 out of 5 by 60.
Rated 5 out of 5 by from so far so good! needed to supplement his alfalfa based hay forage. he's already on SmartCombo Ultra (wonderful stuff!) and this seemed to fit the bill as an add-on. it's now part of his smartpaks. best part, he loves the tase so no problems getting him to eat it.
Date published: 2016-06-30
Rated 5 out of 5 by from Great to take "the edge" off I began using this product about 6 weeks ago, and can already see marked improvement in my gelding. I chose Mega-Mag because it contains far more than just additional Magnesium, including a wide variety of vitamins and minerals for supplementation to my horse's diet. I heard great things at our barn regarding the use of magnesium to help higher strung horses become more calm and focused. My gelding often becomes spooky at the slightest things, jigging one way or another for really no reason. Over the past month I have seen a marked improvement in his behaviors. Last night we were able to walk from our indoor to outdoor arena without balking - this would not have happened a few months ago. I no longer worry that a ray of light on the area floor will cause him to stop mid stride. I am very happy with the results, and have also added this to our high-powered Arab's diet, hoping for the same.
Date published: 2016-04-21
Rated 5 out of 5 by from Perfect for my feeding program Since we feed straight alfalfa this product is perfect to help keep our feed program balanced! Bonus is the horses readily eat the pellets!!
Date published: 2016-03-28
Rated 5 out of 5 by from Highly palatable I had been feeding my broodmare Mare + for a couple of years and she suddenly decided she didn't like it anymore. I spent hours with my feed analysis and the wonderful SmartPak comparison chart and finally decided Mega-Mag was the best replacement. The mare immediately began consuming 100% of this product and has since produced a healthy filly. I had concerns about changing products mid-pregnancy but she was not consuming most of the other product and it was necessary for her to have appropriate nutritional support. I am delighted with the change of products.
Date published: 2014-06-17
Rated 4 out of 5 by from Good results so far Started feeding this to my picky colt who decided he was no longer going to eat his colt vitamin. In just a month he's filled out nicer, his growth is nice and stable and he has a great shine. Even his new hoof growth at the coronet band looks better. Can't wait to see him in a few months on this s
Date published: 2014-03-27
Rated 5 out of 5 by from Great product and economical I have had my 30 year old retired reining stallion on this for three years and have fed it to other horses in the past. Even my most suspicious/finicky eater did not question it in the feed bucket. I am sold on it and have no plans to switch. If I remember correctly I think that I started using it after a review in Mike Plumb's Horse Journal years ago. Price is so reasonable you hardly even need to budget for it.
Date published: 2013-08-30
Rated 2 out of 5 by from Good product but lacks iron This product was recommended to me by a SmartPak employee. My horse ate it without a problem, and my horse looked good and healthy. I was happy with it until I realized that it has no iron in it. My vet told me to find a multivite that has iron because it's important for giving your horse a healthy amount of energy, and my horse tends to be on the lazy side as it is, so I suspect the lack of iron in his diet was making him even lazier. I switched to Accel - pricier, but has everything in it.
Date published: 2013-05-10
Rated 5 out of 5 by from Very Happy with the Results I've waited a little while to comment on this supplement because I wanted to give it enough time to see how things went. Well, I have to say that I have seen a big change in my horse since starting him on this multi- vitamin/mineral supplement. To give a brief background on my horse, he is only four years old and last year he became very sick and we battled for about 6 months to save him. During that time, my vet advised to change his feed to Equine Senior and only give a small amount; that small amount is only two pounds a day, just enough to mix in his supplements to feed. Needless to say, I knew he wasn't getting his recommended vitamins and minerals with his feed, so I searched for something to supplement for that. Since he was being feed Alfalfa, I opted for the Mega Mag. My guy is solid black and since putting him on this, it looks like he has dapples on his coat; he has really bloomed on this stuff. He has put on the weight since adding this to his smart paks, so I am going to have to cut him back on his hay and grain a little now, but he looks awesome!!! He acts likes he feels great so all in all…… I am pleased with this choice so far!
Date published: 2013-04-22
Rated 5 out of 5 by from CALM and FOCUSED I have used Mega-Mag for about 18 months on my 6 year old mare that is used for team roping and endurance. Mega-Mag has turned her into a focused, driven, athlete with heart and bottom. She can stay so focused in the box, yet on an endurance ride, she wants to keep going long past the time I'm ready to give in (maybe I need Mega-Mag). She's a picky eater & she loves it. I love it because it works so well & the cost is super!
Date published: 2012-07-15
Rated 4 out of 5 by from Good value, very palatable My horse eats these without any grain. His coat is looking good and I especially like the price. Will continue to use in my horse's smartpaks.
Date published: 2012-05-01
Rated 5 out of 5 by from Mega Mag Have used the product about 45 days and noticed my horse has more energy , great coat and shine. He started shedding in Jan. as our winters are mild here in Calif. Would highly recommend this product
Date published: 2012-02-17
Rated 5 out of 5 by from Love this product! i purchased mega mag when i rescued my, at the time, just turning 1, baby horse. when i bought him he was just 300 pounds and had absolutely no life in him. I bought this in hopes of getting as much in him as safely as i could. within just a couple of weeks he started showing improvements! I was amazed how quickly the stuff worked on him
Date published: 2012-02-02
Rated 4 out of 5 by from Happy Horses, Happy Owner I bought this product hoping to supplement my horses through the winter months when they aren't on good grass and need extra nutrients and vitamins that can't be provided by hay alone. We've only used it for a month but I can't believe how nice their coats look. Normally that long, scruffy winter hair seems a bit dull, but this winter they are shiny and my palomino's wooly coat has even dappled! They all seem happy and healthy and that makes me happy.
Date published: 2011-12-04
Rated 4 out of 5 by from Good, But Not What I Needed I had my horse on this product for over a month. Then I decided to switch to Barn Bag supplement to save money and get the results I was looking for
Date published: 2011-10-10
Rated 5 out of 5 by from Mega Mag Best vitamin supplement we have ever used! Fabulous!
Date published: 2011-04-29
Rated 5 out of 5 by from Very Economical With all the different brands of multi-vitamin supplements out there, I had to compare them to find the most economical multi-vitamin & mineral supplement on the market. Mega-Mag is very affordable and I like the fact that it comes in pellet form, so I don't have to purchase additional grain. My horse is on an Alfalfa/Orchard Hay diet, but mostly Alfalfa, so I went with the Mega-Mag, instead of the Mega-Cell.
Date published: 2010-12-10
Rated 4 out of 5 by from Good but I wish it didn't have iron in it other then that I love this product, I am switching to mega cell because it has a little less iron.
Date published: 2010-08-12
Rated 5 out of 5 by from Great Product! I have been using this product for over a year and it has really helped our over 20 arabian mare. Her coat looks great and she does better during shows. I took her off it this May and in July her coat was getting long again. So we plan to keep her on it. She has no problem eating it with her grain or alone. I love the pellet form.
Date published: 2010-07-06
Rated 5 out of 5 by from Very Good Product This works very well. The horses eat it well, and it provides just enough calming influence on them.
Date published: 2010-04-30
Rated 5 out of 5 by from Good Product. Great Price I fed this to my horses for a few months and started seeing improvements in their health in ways I didn't really imagine. I had a QH that would eat all of her hay, and her straw bedding within about 2 hours of being in her stall. She had also started chewing on the wood in her stall. I started feeding this to her in a double dose because I thought maybe she was lacking some nutrients from somewhere. Within about a week and a half the wood chewing subsided and she was eating less and less of her bedding. Her coat was looking nice and shiny and she was more apt to run around the pasture instead of looking like a mole hill in the pasture. My 17 year old Arab also began to perk up. And my 2 year old TB rescue was putting on weight more rapidly! I like this product and will continue to feed it to my horses.
Date published: 2010-04-20
Rated 4 out of 5 by from Great for finicky eaters After my horse rejected both Select I and the SmartPak brand, I thought there wasn't a vitamin supplement out there that he would eat - or at least not one properly balanced for his higher Ca diet. Then the SmartPak customer service rep suggested I try this and sent a sample. I liked that it was cheaper, but didn't think I had a prayer of getting it into him. Each sample day and every day since he's devoured it! I don't even know if he realizes it's in his grain. I'd be happier if it better compared to the other two nutritionally, but I'm just glad to be getting something into him as he doesn't need much of any grain and he's well worked regularly.
Date published: 2010-03-09
Rated 5 out of 5 by from great value great value for horses receiving only whole oats and alfalfa/timothy hay
Date published: 2009-11-11
Rated 5 out of 5 by from So far so good I purchased this for a mare with a two month old filly at the barn where I board my horse; the mare is emaciated and I am hoping this helps her.
Date published: 2009-10-15
Rated 4 out of 5 by from Mega-Mag Palatability is good since our horse is a messy eater. Adding vitamins to his grain has always resulted in some of it ending up on the ground, stall walls or his nose. Seems to be less of a problem with Mega-Mag.
Date published: 2009-09-15
Rated 5 out of 5 by from Great Product Mega Mag is a great product. My 2 yo colt is very nervous and excitable. A friend told me about Mega Mag and so I thought. Why not give it a try. So far I have noticed that he is not pacing as much and seems a little more focused. I will keep using this product daily it seems to help.
Date published: 2009-08-17
Rated 4 out of 5 by from Interesting Product I love that this can be customized to the type or hay/pasture provided. I have never had to provide a vitamin supplement before. But in an attempt to "buy local" I switched to locally grown unfortified grains. I do not have a lot to compare this to but it fits my needs. It does smell a bit "funky" but the dose is so small my horse eats it with out complaint.
Date published: 2009-08-14
Rated 5 out of 5 by from Excellent! Somehow,I managed to accidentally order this last time instead of my regular Mega-Cell, and my horse seems to do very well on it! He's on a not-so-great pasture with sandy soil, and bermuda grass, and grass hay in the winter, and a picky eater but eats this up. I had changed his grain and supplement diet this spring, so I'm not sure if it's the Mega-Mag or the other dietary changes, but he looks better than ever this summer! Super shiny coat, good attitude, and less grain than he's been on...and he's still chunky. Excellent value and quality ingredients!
Date published: 2009-06-23
Rated 5 out of 5 by from Mega Mag value For the value, can't beat it; my mare had filled out, looks and is healthy and chows it right down.
Date published: 2009-05-05
Rated 5 out of 5 by from Amazing Supplement This is the best supplement that I have found for my thoroughbreds. They have maintained their body weight and their coats just shine. Their hooves are nice and strong and I would reccommend this to anyone. Easy to add to their grain and they clean up their meals.
Date published: 2009-05-01
Rated 5 out of 5 by from Excellent Product I have been using this product now for about 3 weeks. I cannot believe how shinny my gelding's coat is. He has shed out to an amazing glossy TRUE black. He is an extremely picky eater (does not even like carrots) and he does not even turn his nose at this. I will definitely be purchasing this again for him.
Date published: 2009-04-28
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