Horse Nutrition and Feeding

How to Formulate a Horse Ration

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Formulating an adequate ration for your horse is simple if you remember several things: what the horse requires, what kind of feed will fill those requirements economically, what feeds are palatable and will satisfy the horse yet not encourage wood chewing, tail biting, cribbing, etc., and how much of a given feed the horse can eat. In addition, it will involve a bit of arithmetic.

The coat sheen, eye and expressive ear suggest a well-cared-for horse enjoying an energy-demanding workout. Jumping requires energy as supplied by grain. Excess protein, as so many are prone to provide, will actually decrease a horse's ability to perform at speed and/or distances.

Step 1. Learn to Calculate

The most common feeding problem confronting horse people is figuring what percent of a given nutrient is in a mixed ration. Referring to tables will show how much protein, TDN or calcium is in corn or oats but will not be specific for a mixed feed of unequal parts of corn, oats and soybean meal, for example.

In order to figure the nutrient content of a mixed grain ration, simply multiply the pounds of each of the feedstuffs in the mixture (corn, oats, soybean meal, etc.) by the percent of the nutrient (TDN, protein, calcium, etc.) that each feed contains. Total the amounts obtained and divide by the pounds of feed in the mixture. This procedure provides a weighted average. The common error is to add up the protein content of the corn, oats and soybean meal and divide by three. However, if corn and oats constitute 90 percent of the mixture, they naturally have a greater effect on the average composition than soybean meal, which makes up but 10 percent of the mixture, in this example.

Step 2. Fitting the Feed to Your Horse's Requirements

The next step toward providing your horse's nutrient needs is to relate or compare what is provided in the feed with what the horse needs. When doing this, consider such factors as the horse's capacity and willingness to eat a given feed, feed costs, and ease of feeding.

1. Since forage normally constitutes the major ingredient in the horse's daily ration, compare the nutrient content of the forage (Table 1) with the nutrient requirements of your horse (Table 2). Until you do that, you don't have any idea to what extent you must supplement the ration. It's possible that the forage you have will provide all the nutrients the horse needs.
   
   To illustrate the various points to be made in this bulletin, let's assume that our hay is timothy that was cut at mid-bloom and that we are formulating a ration for a 12-month-old yearling that when mature will weigh 1100 pounds.
   
   
2. Write down the composition of timothy hay (from Table 1) and the nutrient concentration in the ration necessary to meet the yearling's requirements based on what he would consume per day (Table 2), as follows:
   
   

   	TDN %	Protein %	Ca %	P %	Vit. A, IU/lb
   Timothy supplies	49	7.5	.36	.17	4,000
   Horse requires	60	12.0	.50	.35	910

3. Compare the nutrient composition of timothy hay with what the ration for a yearling should contain. You should conclude that:

   a.	Timothy hay is too bulky (lacks concentration of energy). A yearling simply can't eat enough to meet his needs.
   b.	Timothy is inadequate in protein, calcium, and phosphorus.
   c.	Timothy hay provides an adequate concentration of vitamin A.
   d.	To correct the nutrient shortcomings of timothy hay, the grain supplement must be sufficiently rich in these nutrients to compensate for the inadequacies of the hay.

Step 3. Correcting the Nutrient Shortcomings of Timothy Hay

1. The energy shortage of timothy should receive the first consideration. Table 3 suggests a yearling should be fed 15.8 pounds of a ration consisting of equal parts of hay and grain. Such a mixture contains 60 percent TDN (Table 2), and 15.8 pounds would provide 9.5 pounds of TDN, which is about the daily TDN requirement for a yearling (Table 3). If you felt your particular yearling needed more total feed per day with no increase in TDN intake, you might change the hay:grain ratio from 1:1 to 2 parts hay and 1 part grain. About 16.5 pounds of that ration containing about 57 percent TDN would also provide the yearling's daily TDN requirement of 9.5 pounds.
   
   
2. Our next concern is protein. A yearling's ration should contain about 11.3 percent protein (from Table 2). However, a ration consisting of one part timothy hay (7.5 percent protein) and one part grain (corn-oats equal parts) with 10.5 percent protein results in an average protein content in the ration of only 9 percent (7.5 percent plus 10.5 percent = 18/2). Thus, the ration is still deficient in protein.
   
   
3. What protein content should be in the grain ration to correct the deficiency, 14, 17, 20 or 25 percent? Rather than guess, simply determine the difference in protein between what is desired (11.3 percent) and what is in the hay (7.5 percent). In this case, that is 3.5 percent. This 3.5 percent additional protein added to the desired level, 11.3 percent, equals 14.8 percent protein that the grain mix should contain. Thus, 14.8 percent protein in the grain plus the 7.5 percent in the hay = 22.3 percent divided by 2 parts of the ration = 11.2 percent protein in the total ration. So far we are right on!
   
   
4. How does one determine what proportion of feedstuffs to use to end up with 14.8 percent protein rather than 26.5 percent? Let's choose soybean meal (SBM) as a rich source of protein to mix with the corn and oats grain mix. To determine the amount of SBM to add, employ the square method as shown. Enter in the middle what percent you are seeking (14.8 percent). At each left hand corner write in the percent of protein in the SBM (46.6 percent) and in the corn-oats mix (10.4 percent). Then determine the difference between each of the values and 14.8. Those differences are the proportions of each feedstuff necessary to result in a total mix that will contain 14.8 percent protein.
   
   
   
   To convert parts to percent, divide each component's part by the total number of parts, i.e.:
   
   4.4 ÷ 36.6 = 12.2% SBM 31.6 ÷ 36.0 = 87% corn-oats
   
   
5. While 15.8 pounds of a ration consisting of 7.9 pounds of timothy and 7.9 pounds of grain (14.8 percent protein) met the TDN and protein needs, we have no assurance that it contains enough mineral or in the correct calcium:phosphorus ratio to meet the daily requirements of a yearling (Table 3). We calculate the amount of calcium and phosphorus supplied by our ration as follows:
   
   

   
   

   Gaited horses are high-strung and more apt to be stall walkers, and they expend much nervous energy in performing (high head, animated high action, heavy shoes). One of these horses uses more energy in a 15-minute training period than a western pleasure horse uses in several hours. It's the combination of grooming, nutrition, breeding and training that makes them look and perform like peacocks.

   
   

   Calcium:

   7.9 lb timothy x .36% calcium = .028 lb x 454 grams = 12.7 grams calcium. Since the 7.9 lb of grain mix consists of 87.8% corn and oats, and 12.2% soybean meal, multiply those figures by 7.9 pounds to determine the number of pounds each of the mixture constitutes. Thus, 6.9 lb corn and oats mix x .06% calcium (corn has .02% and oats .10% Ca, average .06%) = .0041 lb x 454 grams = 1.9 grams calcium, and .96 lb SBM x .32% calcium = .0039 lb x 454 = 1.36 grams calcium. Total calcium = 12.7 grams from hay + 3.2 grams from grain = 15.9 grams.

   Phosphorus:

   7.9 lb timothy x .17% phosphorus = .013 lb x 454 grams = 6.0 grams phosphorus. 6.9 lb corn-oats mix x .325% phosphorus = .023 lb x 454 grams = 18.4 grams P, and .9 lb SBM x .68% P = .006 lb x 454 grams = 2.7 grams phosphorus. Total phosphorus in the grain ration = 18.4 grams + 2.7 grams = 21.1 grams.






Dressage horses don't perform at speed, but they require hours of daily schooling to acquire and maintain a fine edge of precision execution. They are under stress to perform with a perfection of movement, great suppleness and prompt response to subtle cues.





6. After constructing a table based on the yearling's requirements (Table 3) and the nutrients provided by the 15.8 pounds of ration, it is obvious that inadequate calcium is provided and that the Ca:P ratio is wrong.
   
   

   Feed	lb	Energy TDN lb	Protein Total lb	Ca g	P g	Vitamin A 1000s IU
   Requirement for a 715-pound yearling
   	14.2	9.5	1.9	34	19	15.0
   Amount Provided
   Timothy Grain Total	7.9 7.9	4.0 5.5 9.5	.59 1.20 1.80	12.7 3.2 15.9	6.0 21.1 27.1	28.4

7. Correct the calcium shortage as follows:
   
   

   a.	Subtract the calcium supplied from the requirement (34 g – 15.9 g = 18.1g supplemental calcium needed).
   b.	Decide what calcium source to use. Since we need only calcium, feed grade limestone (calcium carbonate, 39% calcium) is the mineral source of choice.
   c.	How much of the mineral supplement must the yearling consume daily in order to obtain 18.1 grams calcium? (18.1 grams Ca needed divided by 39.0% Ca in the lime-stone mix = 46.4 grams limestone will provide 18.1 grams calcium.)
   d.	What about phosphorus? Since the diet now provides adequate calcium and the ratio of calcium to phosphorus is now 1:1, the excess phosphorus should not be harmful. Had the ration contained less grain, less phosphorus would have been provided.

8. It is one thing to know how much mineral a horse must eat to receive adequate calcium and quite another to know what percent mineral to add to the grain. Our task is to convert 46.4 grams mineral that has been added to each 7.9 pounds of grain to a percentage figure. First, convert all weights to metric (7.9 pounds divided by 2.2 pounds = 3.59 kg feed). Convert 46.4 grams of limestone to .0464 kg, and .0464 divided by 3.59 kg feed equals 1.29 percent limestone added to the grain would assure adequate intake of calcium.

If your hay had been half alfalfa, adequate calcium would have been provided. Providing a salt-limestone mix free-choice would also help alleviate the mineral shortage. But the fact remains that we can't assume that hay and grain always provide adequate nutrition for horses. To provide the best rations, we must do more than merely guess at what is or is not provided.

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