You may recall my student/friend, TJ spent a term using Junior as her project for her Equine Nutrition course in my college's Equine Science Department, taught by my Vet/Friend. She (TJ) began to teach me what she learned. I didn't know the first thing about Equine Nutrition until late November. Now I know a little more, or at least think I do. Science and Math were not my strong subjects in school and creating rations takes both. Don't be afraid. It shouldn't be nearly as complicated as I made it, but as my mother often reminds me, I've never really done anything the easy way.
I won't try to fit everything I learned in to this post, but here goes. Horses evolved grazing on grass and other ground forage. They ate for about 18 hours every day. They ate slowly all day long in order to get the nutrients they needed. Once we domesticated them we made them work all day instead of eat. We needed to feed them more calories and nutrients in more concentrated amounts, so we began feeding them grain. And the horses loved it. So now we have two forms of feed: Forage and Concentrates (grain) to feed. Ideally for a mature horse a 100% Forage diet is best but that's not always available or practical, so a 90:10, 80:20, or 70:30 F:C ratio becomes common. You really don't want to go below the 70% forage.
The NRC guidelines will tell you your horse's daily requirements: National Research Council Table
You start with bodyweight. Most horses in light work should have 1.5-2.5% of their bodyweight per day. We'll take that 2% of bodyweight (for JR we estimated it's 1150lbs) which is 23lbs and make 80% of that Forage and 20% of that Concentrates.
In addition to ratios and percentages, you need to make sure the horse is getting the right amount of energy, so you find out how many Mcals are in your Forage and Concentrate. In order to find out how many Mcals are in your Concentrate, you can call your feed company. For your Forage, you can have it analyzed for a fee. You should have your hay sampled each time you get a new batch.... yeah right. Like anybody does that!
Then you just make sure the horse is getting all the vitamin and mineral needs and you're all set. Sound complicated? It is, but it doesn't have to be. The reality is that the hay he's being fed today probably isn't at all the same as the hay we sampled, but hay doesn't differ all that much if it's the same type (ie Grass vs. Alfalfa). It's all a bunch of guess work, really. Most equine feeds have the nutrients they need.
Bottom line is to feed good quality forage and add grain or ration balancers if needed. If your horse is healthy, in good weight, and is performing how you want him to, then you're doing just fine. We're NOT doing just fine. Junior is overweight. He was underweight when I got him in September of 2009, but the pictures on his coggins papers from October 2007 show him to be overweight, too. It seems he's an easy keeper.
His current ration was supposed to be 4 flakes (12-13lbs) of hay and 6lbs grain/day, or at least that's what we thought he was getting. It is difficult to estimate with the "1/2 scoop" method and when I actually weighed on of his feedings I found he was getting 5.5lbs of grain IN ONE MEAL. So he was getting way more than he should've been getting. I began weighing and pre-bagging my own feed the next day.
We're going to go with 2% of his bodyweight and an 80:20 ratio. Junior has a BCS of around 8 so he could really stand to lose a few lbs. Since September he's been feed approximately 25% more DE (Digestible Energy) than he needs, NOT including the grazing forage he was still getting at the time. So we're going to start with 2.0% and then if he doesn't get into a better BCS I'll drop him to 1.5% but it will take a while to see progress.
He'll be getting 6 flakes of hay (approximately 18-19.5lbs) and 3lbs of grain per day. The Concentrate will be a 50/50 mix of the barn grain and Seminole Wellness Safe & Lite. The mixture is purely to save $$. Since the hay will be costing me an extra $30/month using some of the grain I'm already paying for with my board will be better. The Safe & Lite has 26% fiber which is really high and will actually bring up the digestibility of the fiber in the forage.
You shouldn't make drastic changes in your horse's feed, so this past week I've gradually lightened his grain from the 5.5lbs he was getting to 3lbs. Over this next week, that 3lbs will lighten to 1.5lbs and he'll get one extra flake starting midweek. Then over the next week I'll slowly swap out half the barn grain for the Safe & Lite, and add the 6th flake. Then we'll have to see how it goes. I'll take the 5th and 6th flakes away during the summer good grazing time and hopefully he won't balloon again.
Oh, and I stopped the Smart Calm. When I started pre-bagging I did every-other day, than a third day, and then just stopped it. I haven't noticed a difference yet, so that's good. I have a whole month of it sitting and waiting to see if I need it, but I do not anticipate that I do. The Safe & Lite contains Magnesium anyway.
In addition to what TJ taught me, I read this book: Equine Nutrition and it helped me a lot. It's written for the average horse owner in plain English.