A575
Nutrition


selecting the diet | calculating forage, concentrate, and pasture intake | analyzing feedstuffs | nutrient requirements | evaluating and correcting diets | Pearson square procedure  


Introduction: One of the most important aspects of equine health is proper nutrition. Many health or performance problems can be prevented or corrected with good nutrition. Providing good nutrition is not difficult if the basic concepts are understood. Fresh water, good quality hay, grain (when needed for extra energy), and a vitamin/trace mineral source are the essential components of quality nutrition.

The following are a few definitions important for understanding nutrition:

  1. Energy - This is often measured as Digestible Energy (DE), Metabolizable Energy (ME), and Net Energy (NE) in units of mega-calories per pound of feed, and relates to that portion of the feedstuff that can be digested to create energy. Total Digestible Nutrients (TDN) is also used. Proper energy levels are essential for performance and proper body condition. One kilogram TDN equals approximately 4.4 DE (Mcal), 3.6 ME (Mcal), and 2.0 NE (Mcal). Conversions for estimating DE from crude fiber amounts on a product label can be found in table #6 at the end of this discussion.

  2. Protein - This is the basic building block for all growth of muscle, bone, hair, and hoof. Protein is also essential for just about every metabolic/life supporting process in the body. Attention should be placed on the protein content of every feed that is used.

  3. Fiber - This is the indigestible portion of a feed. Plenty of fiber from forages is important in maintaining good health and preventing colic.

  4. Dry Matter - This describes the percentage of feed that does not contain water. All grains and hays contain some percentage of dry matter. This may vary from 75-95%, depending on the particular feed and harvesting conditions. The percentage of moisture and the percentage of dry matter equal 100%. If 10 lbs. of feed is 90% dry matter, then 9 lbs. of that feed would be dry matter.

  5. Vitamins - The major vitamins are vitamin A, B, D, and E. Vitamins A, B, and E must be supplied by the feed, while vitamin D can be synthesized by the animal with the help of sunlight. Vitamins are essential for normal and efficient biochemical functions for growth and activity within the body.

  6. Minerals - Essential minerals include calcium and phosphorus. Both of these should be balanced in the diet at a 2:1 ratio. Salt is also a major mineral. Essential trace minerals are copper, zinc, iron, and selenium. Many horses should be given a properly balanced mineral/vitamin supplement. Alfalfa diets typically require supplements low in calcium and high in phosphorus. Grass hay or pasture diets generally require supplements high in calcium and low in phosphorus. A common supplement for many horses is a free-choice, trace-mineral salt source, either loose or in block form.

Table #1 - Common minerals and vitamins required by the average 1,100 pound (mature weight) horse:

Class
(1100 lbs mature body wt.)
Age in Months *Calcium *Phosphorus *Magnesium *Potassium *Vitamin A
   

   

% Grams % Grams % Grams % Grams IU/lb    103 IU
Growing    6    0.58    32.5    0.32    18    0.08    4.1    0.30    13.0    800    10
Growing    12    0.44    31.5    0.24    17.5    0.08    5.6    0.30    18.0    925    15
Growing    24    0.32    29    0.18    16    0.09    8.4    0.31    27.6    1065    20
Maintenance    >24    0.24    20    0.17    14    0.09    7.5    0.30    25    830    15
Late Pregnancy
(Last 3 months)   
>60    0.43    35    0.33    27    0.10    8.9    0.37    29.7    1660    30
Lactation 
(First 3 months)   
>60    0.52    56    0.34    36    0.10    10.9    0.42    46    1250    30
Lactation 
(3 months to weaning)   
>60    0.36    36    0.22    22    0.09    8.6    0.33    33    1370    30
Light Work
(Pleasure)   
>60    0.30    25    0.22    18    0.11    9.4    0.37    31.2    1220    22
Moderate Work 
(Ranch, cutting, roping)   
>60    0.31    30    0.23    21    0.12    11.3    0.39    37.4    1100    22
Heavy Work 
(Racing, polo)   
>60    0.35    40    0.25    29    0.13    15.1    0.43    49.9    890    22

* Some researchers recommend feeding values that are 1.25 - 3 times higher than the above National Research Council (NRC) values.

There are many factors that affect the daily feed requirements of a given animal. Some of these are listed below:

  1. Breed and size
  2. Age (foal vs. adult)
  3. What the animal is used for (pleasure, broodmare, competition, etc.)
  4. Environment and climate
  5. Health status (teeth and parasite control)
  6. Attitude (calm or high strung)

Table #2 - Common classes of horses, all with different nutritional needs:

Growing horses   

Broodmares   

Adult Horses

Suckling foals   

Barren   

Idle

Weanlings   

Early pregnant   

Light work

Yearlings   

Late pregnant   

Moderate work

Long yearlings   

Early lactation   

Heavy work

Two year old   

Late lactation   

Geriatric

 

Selecting the Diet and Amounts to Feed:

Introduction: Good pasture forage and/or hay can supply sufficient nutrition for a typical mature horse. The addition of concentrates (grains) may be required for animals that are growing, working, or nursing a foal. Care should be taken to prevent animals from becoming overweight on good pastures or by over feeding. The following table lists the expected amounts of forage and concentrate a horse may consume depending on its class. Horses will generally consume 1.5 to 3.5% of their body weight in feed per day. Ideally, to maintain proper gut function, it is recommended that at least 1% of the horse’s body weight is fed as forage.



Table #3 - Forage and concentrate a horse may consume:

Class of Horse % of Body Weight % of Diet
Forage Concentrate Forage Concentrate

Maintenance

1.0-2.0

0-1.0

50-100

0-50

Pregnant mare

1.0-2.0

0.3-1.0

50-85

15-50

Lactating mare (early)

1.0-2.5

0.5-2.0

33-85

15-66

Lactating mare (late)

1.0-2.0

0.5-1.5

40-80

20-60

Weanling

0.5-1.0

1.0-3.0

30-65

35-70

Yearling

1.0-2.5

0.5-2.0

33-80

20-66

Performance horse

1.0-2.0

0.5-2.0

33-80

20-66

When choosing a particular hay, the following suggestions should be used:

  1. Consider the color and cutting dates. Green, freshly cut hay generally contains more vitamins and nutrients. Third and fourth cutting hays may be excellent quality, but too rich in protein and low in fiber for the particular needs of the horse.
  2. Different types of hay vary widely in amounts of protein, energy, vitamins, and minerals. A forage analysis is the only way to be sure of the nutrient levels provided by a particular feed.
  3. Pick the hay quality that meets the specific horse’s needs for stage of growth, age, and level of activity. Often, the highest quality hay is "too good" and can create digestive system problems.
  4. Evaluate the hay for general condition. Do not feed dusty or moldy hay. Any mold or dust can cause chronic respiratory problems. (See heaves on page E305 for additional information.)

When choosing a specific grain, the following suggestions should be used:

  1. Evaluate the color and smell. All grains should be brightly colored and have no foul odor. Changes in color and smell may indicate bacteria or mold contamination. Avoid grain that is dirty or contains rocks, sticks, etc.
  2. Grain that is high in moisture or light in weight (lbs. per bushel) will have a lower density of nutrients.
  3. Do not overfeed grains. Feed the appropriate amount for the age, stage of growth, and level of activity. Many mature horses, doing light work, do not require any grain if they are on good pasture or are fed quality hay.

Calculating Forage, Concentrate, and Pasture Intake: It is always important to weigh each forage or concentrate that is being fed to the horse. If the horse is grazing pasture, the amount of pasture being consumed can be determined by calculating all the digestible energy (DE) the horse is receiving from known quantities of hay and/or concentrate. Next, subtract the DE intake from hay and/or concentrate from the horse’s daily energy requirement. Then, to get the horse’s estimated dry matter intake of pasture, divide this number by the pasture’s calculated energy density. For example, a yearling that weighs 725 pounds with an average daily gain of 1.25 lbs/day should require about 20.4 Mcal DE/day (taken from table #4). If this yearling is eating 5 lbs of sweet feed (6.75 Mcal DE total) and 6 lbs of mature alfalfa hay (5.64 Mcal DE total), then it must be consuming around 8 Mcal of DE from pasture. The horse in this example is grazing on a pasture that is mostly orchard grass that has a 1.04 Mcal/lb DE. This means that this yearling must consume about 8 lbs of pasture dry matter per day to meet his energy requirements. Realize that this is just an estimate of the pasture the horse is consuming and that miscalculations can occur. Many miscalculations occur because of under or over estimating the amount of hay and grain the horse is consuming.

 

Analyzing Feedstuffs:

Introduction: After nutrient requirements are established, the various feedstuffs to be fed should be sampled and analyzed for nutrient content. Forage and feedstuff analysis is an important management tool in the development of a proper feeding program. Knowledge of the quality of a feed helps determine where, when, and how much of a particular feed to use. Evaluating feed quality without an analysis can be extremely misleading.

Step 1 - Choose the Feeds to be Tested: The feedstuffs chosen for analysis should form the basis of the ration. This will usually include samples of each different type or cutting of hay and any other roughages. The nutrient composition of roughages varies greatly from year to year and from farm to farm, making yearly analysis a necessity.

Home raised grains should be tested every 2 years to check nutrient quality compared to expected values. Nutrient composition of feeds such as corn and soybean meal vary significantly, and depend upon variety, weather, and processing conditions. Frequent testing of the energy and protein ingredients in mixed feeds, such as growing or lactating rations, is also necessary. 

Step 2 - Collect the Feed Sample: Accurate feed analysis begins on-farm with proper feed sampling techniques. Collection of a representative feed sample is the most important step in feed analysis. Use these guidelines when collecting feed samples:

Hay Samples: To sample hay properly, a hay core sampler is a necessity. Many feed company representatives, county extension agents, and a few veterinarians have core samplers. Place the hay corer into the middle of the narrow end of square bales, or the rounded side of large round bales, and drill to the center of the bale. When sampling from large round bales, an extender is added to the core sampler so that the bale center can be reached. Proper sampling practices ensure that the sample obtained will include the same proportion of leaves and stems that is present in the entire bale. Sample a minimum of 10-12 bales from different locations in the storage area. Better yet, set aside bales that are to be sampled as the hay is being stored. This will avoid hay being buried under or behind other hay in the storage area and allow a more representative sample to be collected. Mix the samples together in a clean, dry plastic pail. A two-handful subsample sealed in a plastic bag and well-labeled is sufficient for laboratory analysis. Flakes of hay or samples grabbed by hand are not representative samples and analytical results will be inaccurate. Many labs will refuse to accept inappropriate samples.

Dry Grains: Sample dry grains by hand or with a grain probe. Sample from various areas in the storage bin, and mix all subsamples in a clean, dry pail. Remove two handfuls of the combined mixture and place the sample in a clearly labeled plastic bag to be sent to the lab.

Pasture: Because horses tend to be "spot" grazers, pasture analysis is more difficult. Generally, only those areas that are heavily grazed should be sampled, rather than the entire pasture. Collect random handfuls of forage from several locations in the heavily grazed area. These samples should be collected at about the same height the animals will be grazing the forage. Once collected, the samples from a certain pasture should be combined and allowed to air dry. Air drying is accomplished by hanging the forage inside a burlap bag for approximately a week. Once dried, these samples can be sent to a laboratory for analysis.

Step 3 - Submit the Feed Samples: Once the representative sample is properly collected, the process is not yet complete. Samples must be accurately labeled and described. Feed analysis laboratories require a completed "sample input" form to accompany the samples. The input form information and proper sample identification are extremely important to enable the lab to perform the correct analytical procedures. When submitting hay samples, indicate the type (grass, mixed or legume) and appropriate cutting (i.e. first, second, etc.). Follow these general guidelines to determine the type of hay being submitted for analysis:

GRASS = < 25% legume (alfalfa, clover, etc.) in the sample
MIXED = 25-75% legume in the sample
LEGUME = > 75% legume in the sample

A good policy to follow when submitting samples is to include any and all information that will help the laboratory do the best job possible. A list of available laboratories can be obtained from the Cooperative Extension Service.

 

Nutrient Requirements:

Introduction: The goal of ration evaluations is to compare a horse’s daily nutrient intake to a set of requirements; however, the question arises on what nutrient requirements should be used? Currently, there are fairly standardized recommendations for protein and energy (digestible energy). Much of this information comes from the studies performed by The National Research Council (NRC). Most of the following recommendations come from the NRC recommendations and also from the research performed by the Kentucky Equine Research, Inc. The following requirements are only general suggestions and should not be used as the only guide in developing or correcting a horse’s diet.

Energy: This is often the key area of focus when evaluating a ration. Horses that are nursing, growing, or doing heavy work have relatively high energy requirements. Cold, severe weather conditions increase energy needs. The following list contains equations for determining the energy requirements (digestible energy) for different classes of horses:

  1. Weanling DE (Mcal/day) = 1.4 + (.0136 X BW1) + (4.54 X ADG2)
  2. Yearling DE (Mcal/day) = 1.4 + (.0136 X BW) + (7.27 X ADG)
  3. 2 yr old DE (Mcal/day) = 1.4 + (.0136 X BW) + (9.1 X ADG)
  4. Maintenance DE (Mcal/day) = 1.4 + (.0136 X BW)
  5. Early pregnant3 DE (Mcal/day) = Maintenance DE
  6. Late pregnant4 DE (Mcal/day) = (Maintenance DE) X 1.2
  7. Early lactation5 DE (Mcal/day) = (Maintenance DE) + (.04 X BW X 0.36)
  8. Late lactation6 DE (Mcal/day) = (Maintenance DE) + (.03 X BW X 0.36)
  9. Light work DE (Mcal/day) = (Maintenance DE) X 1.25
  10. Moderate work DE (Mcal/day) = (Maintenance DE) X 1.50
  11. Heavy work DE (Mcal/day) = (Maintenance DE) X 2.00

1BW = body weight in pounds
2ADG = average daily gain in pounds per day (weanlings = 1.75 lbs; yearlings = 1.25 lbs; 2 yr olds = 0.50 lbs)
3Early pregnant = First 8 months of pregnancy
4Late pregnant = Last 3 months of pregnancy
5Early lactation = First 3 months of lactation
6Late lactation = Second 3 months of lactation

Table #4 - Common requirements for both energy and protein for different classes of horses with a mature weight of 1,100 pounds:

Class

Age in Months

Weight of Animal in lbs.

Protein Requirements Pounds

Protein Requirements 
%

Digestible Energy (DE) Mcal/day

Growing

6

500

1.78

14.5

16.1

Growing

12

725

1.99

12.6

20.4

Growing

24

1000

2.11

10.4

19.6

Maintenance

>24

1100

1.45

8

16.4

Early Pregnancy 
(First 8 months)

>60

1100

1.45

8

16.4

Late Pregnancy 
(Last 3 months)

>60

1100

1.91

10.6

19.7

Lactation 
(First 3 months)

>60

1100

3.15

13.2

32.2

Lactation 
(3 months to weaning)

>60

1100

2.31

10.7

28.3

Light Work
(Pleasure)

>60

1100

1.81

9.8

20.5

Moderate Work 
(Ranch, cutting, roping)

>60

1100

2.17

10.4

24.6

Heavy Work 
(Racing, polo)

>60

1100

2.90

11.4

32.8

Protein: Protein is also an essential component to any diet. Broodmares and growing animals require additional protein in the diet. In general, if the diet contains sufficient energy, it often contains sufficient protein.

Evaluating Body Condition: Determining the horse’s body condition is essential in making any diet changes. Use the information found on page B950 to help determine a horse’s body condition before making any changes to a ration.

Table #5 - Nutrient analysis of common feeds and supplements:

Type of Feed Dry Matter 
Digestible 
Energy (DE) 
Mcal/lb
Protein 
Calcium 
%
Phosphorus 
%
Hays (as fed)  

Alfalfa (mid bloom)

91

0.94

16.0

1.24

0.22

Bermuda grass

90

0.85

10.6

0.35

0.24

Bluegrass

92

0.72

8.2

0.24

0.25

Oat hay 90 0.79 8.6 0.29 0.23

Timothy (mid bloom)

89

0.80

8.6

0.43

0.20

 
Pasture (dry matter)  

Alfalfa

100

1.34

22.2

1.71

0.30

Bermuda grass

100

1.08

12.6

0.49

0.27

Bluegrass

100

0.95

17.4

0.50

0.44

Clover

100

1.14

25.8

1.27

0.35

Fescue

100

1.01

15.0

0.51

0.37

Orchard grass

100

1.04

12.8

0.25

0.39

Pangola grass

100

0.89

9.1

0.38

0.22

 
Grains and Supplements (as fed)  

Barley

88

1.49

11.7

0.05

0.34

Beet pulp

91

1.06

8.9

0.62

0.09

Corn

88

1.54

9.0

0.05

0.30

Molasses

78

1.20

6.6

0.12

0.02

Oats

89

1.30

11.8

0.09

0.34

Soybean meal

89

1.43

44.5

0.35

0.63

Sweet feed

89

1.35-1.40

10.8

0.06

0.35

Note: All numbers provided in the previous tables were taken from research performed by the Kentucky Equine Research, Inc. and the Nutrient Requirements of Horses, fifth revised edition, 1989, National Academy of Science, National Research Council.

 

Evaluating and Correcting Diets: (The specific numbers used in the following examples are taken from tables #4 and #5. The protein and energy levels can also be found on the label of many grain products. Feedstuff analysis is highly recommend on all forages and concentrates with unknown values.)

Example A: The yearling in this example is currently eating 2.5% of her body weight or 18.13 lbs of alfalfa hay (0.94 Mcal/lb DE and 16% protein) per day. The yearling, however, has a body condition score of only a three (3). No mineral is provided. Good water in a heated tank is readily available. Using information from table #4, note that a 725 pound yearling filly needs approximately 20.4 Mcal/day of digestible energy (DE) and 12.6% protein in the diet.

Step #1: Determine if this yearling is consuming the appropriate amount of both forage and concentrate by using the suggestions found in table #3.

According to table #3, most yearlings should consume 1.0-2.5 % of their body weight in forage and 0.5-2.0% of their body weight in concentrate.

In this example, the yearling seems to be consuming the maximum amount of forage per day; however, because her body condition is lacking, she still needs additional energy. Concentrates are usually great sources for additional energy and should make up some proportion of her ration. It is also determined that the yearling can not consume more than about 18 lbs total of feed per day.

Step #2: Calculate the digestible energy (DE) provided by the alfalfa hay to the yearling. This is done by multiplying the Mcal/lb DE of the alfalfa by the amount the yearling is consuming.

0.94 Mcal/lb X 18.13 lbs = 17.04 Mcal DE Total

Conclusion: Based on the fact that the yearling has a BCS of 3.0 and her Mcal DE requirement is 20.4, she requires additional energy. This calculation also supports the need for additional concentrate in the diet.

Step #3: A sweet feed with 1.40 Mcal/lb DE and 10.8% protein is chosen to be used as the concentrate portion of the diet. It is also determined that the owner will feed 18 lbs total of both the hay and sweet feed. This means that each pound of feed consumed must contain an average of 1.13 Mcal/lb DE (20.4 / 18 = 1.13). To determine the exact amounts of hay and sweet feed to feed, a Pearson square method is being used:

The Pearson Square Procedure:

A. Draw a square similar to the one found in B.

B. Place the desired nutrient amount or percentage (DE, TDN, protein, etc.) needed to balance the requirements of a specific animal in the center of the square. In this example, 1.13 Mcal/lb of feed is her digestible energy (DE) requirement if she will only consume 18 lbs of feed total.

C. Place the name and nutrient amount of the primary feed being fed (usually pasture, hay, etc.) in the lower left hand corner, and the name and nutrient amount of the supplemental feed in the top left hand corner.

Sweet feed
1.40 DE (Mcal/lb)

 

Alfalfa hay
0.94 DE (Mcal/lb)

 

* Note: If the nutrient requirement amount or percentage in the center of the square is lower than the primary feed, the primary feed is adequate and no supplementation is necessary. However, if it is higher, then proceed to D.

D. Calculate the difference between the feedstuff to be fed and the basic nutrient requirement in the center of the square. This number should be placed in the opposite corner following the arrows. In this example, 1.40 minus 1.13 = 0.27, and 0.94 from 1.13 = 0.19.

Sweet feed
1.40 DE (Mcal/lb)

0.19 Sweet feed

Alfalfa hay
0.94 DE (Mcal/lb)

0.27 Alfalfa hay 

E. The numbers to the right of the square indicate how many parts of the total ration should be sweet feed (0.19) and alfalfa hay (0.27). The numbers 0.19 and 0.27 added together indicate that the total ration contains 0.46 parts.

F. Now the total amount to be fed of both the grain and hay can be calculated.

Amount to feed:

Alfalfa: 0.27/0.46 X 100 = 59% of the total ration should be hay
Sweet feed: 0.19/0.46 X 100 = 41% of the total ration should be grain

Alfalfa hay: 0.59 X 18 = 10.6 lbs hay on a dry matter (DM) basis
Sweet feed: 0.41 X 18 = 7.4 lbs grain on a dry matter (DM) basis

Check the Results:

Alfalfa hay: 0.94 Mcal/lb DE X 10.6 lbs = 9.98 Mcal DE
Sweet feed: 1.40 Mcal/lb DE X 7.4 lbs = 10.36 Mcal DE
Total Mcal DE: 9.98 + 10.36 = 20.34 Mcal DE total

Conclusion: The ration now meets the energy requirements for this yearling. Looking back at the percentages of hay and sweet feed to be fed (59% and 41%), and comparing these to the ones found in table #3, the yearling should be able to consume the above amounts of hay and sweet feed.

Step #4: Next, determine if the current diet meets the yearling’s protein requirements of 1.99 lbs or 12.6%.

Alfalfa hay: 16% X 10.6 lbs = 1.70 lbs of protein from the hay
Sweet feed: 10.8% X 7.4 lbs = 0.80 lbs of protein from the sweet feed
Total lbs of protein: 1.70 + 0.80 = 2.50 lbs of protein total
2.50 / 18 = 13.8% protein

Conclusion: The ration actually exceeds what the yearling may require for protein. In some cases, it may be necessary to select a hay that still gives similar energy levels but has a lower protein. For now, it is recommended to focus on the energy and see if the yearling gains some extra body condition. Once this is accomplished, changes can be made to the protein levels. This yearling also needs a free-choice trace-mineral salt source.

 

Example B: A current horse owner just purchased a new 4 year old gelding to use for pleasure riding. This horse weighs 1,100 lbs and is in good body condition. Determine how much of the current diet being fed to the other horses this new horse requires. The current feeds on hand include a concentrate mixture (1.30 Mcal/lb DE) and timothy hay (0.80 Mcal/lb DE). From table #4 it is determined that this horse has a total DE requirement of 20.5 Mcal/day.

Step #1: To start with, determine how much of the diet should be roughage. Use the suggestions in table #3 to help estimate the amounts that should be fed. In this example, the horse is not expending excessive amounts of energy, so the bulk of his ration will be hay and a minimum amount will be concentrate.

Amount of hay = 2.0% X Body Weight
0.02 X 1,100 = 22 lbs of hay on a dry matter (DM) basis

Step #2: Calculate the digestible energy (DE) provided by the timothy hay to the gelding. This is done by multiplying the Mcal/lb DE of the hay by the amount the gelding will be consuming.

0.80 Mcal/lb X 22 lbs = 17.6 Mcal DE Total

Conclusion: Based on the fact that the gelding has a DE requirement is 20.5, he requires 2.9 Mcal DE/day (20.5 - 17.6) additional energy. The remaining DE should be supplied by the concentrate portion of the diet.

Step #3: Determine how much of the concentrate (1.30 Mcal/lb DE) should be fed in addition to the hay. This is done by simply dividing the amount of additional energy the horse requires by the amount of DE per pound of feed the concentrate contains.

2.9 / 1.30 Mcal/lb = 2.23 lbs of concentrate on a dry matter (DM) basis

Step #4: Because very few feeds are actually 100% dry matter (DM), convert the above amounts of hay and concentrate from a DM basis to an as-fed basis. To do this, divide each amount of hay and concentrate dry matter by the percent of dry matter in that feed (taken from table #4 or the actual concentrate feed bag).

Timothy hay: 22 lbs / 89% DM = 24.7 lbs of hay as fed
Concentrate: 2.23 lbs / 88.2% DM = 2.52 lbs of concentrate as fed

Conclusion: This means that the gelding really requires 24.7 lbs of hay and 2.52 lbs of concentrate to fill his nutritional requirements. Try this ration for the first few weeks to months and monitor the gelding’s body condition. If he becomes too heavy or too thin, adjust his ration as shown in Example A.

Summary: The information provided in the previous tables is based on averages for all animals and all feedstuffs. Different individuals within each class can have very unique nutritional needs. Because of this, use the horse’s body condition as the determining factor when making adjustments to a ration. Do not force a horse to eat exactly what is calculated on paper and neglect the horse’s actual body condition. The following suggestions can be used when trying to evaluate weight changes and rations:

  1. Weigh the horse regularly over several weeks. If weighing is not a possibility, use the suggestions found on page B950 to calculate a horse’s weight. Also use the information about body condition scoring. Body condition is often a more reliable indicator of the nutritional status than simply using body weights. Realize that horses with the same weight will not have the same BCS. A horse with a BCS of 5 should be used as the standard; all other animals should be compared to this "average" horse. A horse with a BCS of 5 is not too fat or too thin; the ribs cannot be seen, but can be felt.
  2. Calculate average daily weight gains for growing horses and use these to determine energy requirements.
  3. Weigh each feedstuff and verify that the horse is really consuming the amounts used for calculations. Watch for horses that may waste some of the measured feed. If possible, feed the horse in feeders that are off the ground and have a "catch area" for smaller feed particles.
  4. Have a feedstuff analysis performed on every feed with unknown nutrient values. Because the nutrient values differ so much between similar feedstuffs, table #5 should only be used as a general guide.
  5. Provide plenty of clean, fresh water on a daily basis. Do not rely on snow for winter water supplies. To properly digest and move the feed through their digestive system, horses need plenty of water. Impactions and colic are common problems associated with a lack of hydration.

Converting crude fiber on a feed tag to digestible energy (DE) Mcal/lb: Many feed tags do not contain the actual DE; therefore, it is often necessary to use the crude fiber and crude fat percentages to determine the DE (Mcal/lb) of the grain mix. Use the following table to help make the conversion:

Table #6 - Relationship of crude fiber to expected digestible energy in conventional and fat added grain mixes:

Crude fiber indicated on feed tag If crude fat on tag is <3% 
(indicating no added fat) DE (Mcal/lb) of feed will be approximately
If crude fat on tag is approximately 8% 
(about 5% added fat) DE (Mcal/lb) of feed will be approximately 

4

1.55

1.65

6

1.45

1.55

8

1.35

1.45

10

1.25

1.35

12

1.15

1.25

 

Table #7 - Measurements and conversion formulas that are often used when formulating rations:

Measurement

1 kilogram (kg)   

=

2.2 pounds

1 kilogram   

=

1000 grams

1 milligram   

=

0.001 gram

1 kg TDN   

=

4.4 DE (Mcal)

1 kg TDN   

=

3.6 ME (Mcal)

1 kg TDN   

=

2.0 NE (Mcal)

Convert pounds to grams   

 

Multiply pounds by 453.6

Convert kilograms to pounds   

 

Multiply kilograms by 2.2