Effect of Underfeeding a Higher-Intake Concentrate on Nutrient Intake and Cost

SITUATION: You are feeding less concentrate because your horse is too heavy.

TYPICAL DECISION: You decide to feed a minimal amount of a concentrate, unaware that the feed is designed to be fed at a minimum of 6 pounds per day (i.e. Brand “S”; an actual pelleted concentrate available on the market today) instead of Tribute Equine Nutrition’s ESSENTIAL K , which is designed to be fed at low levels.

NUTRITIONAL INTENT: Correct approach is to feed fewer calories and lower starch.

QUESTION: What does underfeeding a poorly designed concentrate do to the intake of critical nutrients other than calories?

COMPARISON: Nutrients supplied by 2 pounds of Brand “S” compared to nutrients supplied by 2 pounds of ESSENTIAL K.



Two pounds of Brand “S” supplies 2,840 kcal, whereas 2 pounds of  ESSENTIAL K supplies 2,640 kcal. Horse will lose weight more quickly on ESSENTIAL K.

Starch intake with 2 pounds of Brand “S” is 5- times higher than 2 pounds of ESSENTIAL K. Blood glucose and insulin response to Brand “S” will be much greater, and will decrease the horse’s ability to lose weight by impairing the breakdown of body fat. Other negative effects of high starch may also be seen (hyperactivity, ulcers, colic etc.)


The protein supplied by 2 pounds of Brand “S” is half of that supplied by 2 pounds of ESSENTIAL K. Horses with restricted protein intake often lose body condition and topline strength. In addition, the protein in Brand “S” is primarily from wheat middlings, grossly inferior to the quality of protein in ESSENTIAL K supplied primarily from extruded whole soybeans. This will exacerbate the effects of low protein in the diet.


Mineral nutrition is especially important in young, growing horses, broodmares and horses with minimal free-exercise. Lack of exercise can cause demineralization of bones in mature horses. 
The analysis shows the intake of calcium, phosphorous and copper is nearly 2.5-fold lower for Brand “S” compared to ESSENTIAL K. Intake of zinc is 40% lower for Brand “S” compared to ESSENTIAL K.

Many horse owners make the mistake of only considering COST PER BAG instead of COST PER DAY in their feeding program.

COST PER BAG (cost per pound)
Consider the following example.

To calculate cost per pound for a feed, we take the cost per 50# bag and divide by 50, 

                                    Cost per pound =  cost for 50# bag 
REAL EXAMPLES (prices may vary with time and location):

  • Brand “S” –
    • $15.00 per bag ($15.00/50) = $0.30 per #
    • $25.00 per bag ($25.00/50) = $0.50 per #

Read the back of the bag or the tag to find the recommended feeding rate for the product, then multiply the COST PER POUND x RECOMMENDED FEEDING RATE.

  • Recommended amount of Brand “S” –
    • 6# per day @ $0.30/# = $1.80 per day
  • Recommended amount of ESSENTIAL K –
    • 2# per day @ $0.50/# = $1.00 per day

Now, as stated at the top of this article, your horse is getting too heavy, so you decide to decrease his grain intake. You go from the recommended 6 pounds per day to 2 pounds per day. This will decrease his calorie and starch intake, but also reduces his intake of ALL other nutrients, as we saw above.

What about the effect on cost? Obviously, going from 6 pounds per day (at $0.30 per pound = $1.80 per day) to 2 pounds per day will decrease your cost per day for the grain to $0.60 per day. As seen above, the cost per day for ESSENTIAL K at 2 pounds per day is $1.00.

Your decision is whether the additional amino acids, vitamins and minerals supplied by ESSENTIAL K plus the reduction in calories and 5-fold reduction in sugar/starch are worth $0.40 per day.

If not, an alternative approach is to say you are happy with the amount of amino acids, vitamins and minerals supplied by 2 pounds of the 6 pound-per-day product. The question is then how much ESSENTIAL K would it take to supply that amount of nutrients and what would it cost??

Below are two charts that answer these questions:
So, except for zinc, 0.8 to 1.0 pounds of ESSENTIAL K will supply the same amount of protein, calcium, phosphorous and copper as 2 pounds of Brand “S”. It will also further lower the horse’s calories and sugar/starch intakeThe same principle would 
apply for most other crticial nutrients, but for the sake of space, only the most critical nutrients are addressed here.

 ….and what about the impact on COST PER DAY??

The cost per day for the lower amount of Brand “S” is $0.60. The cost for the amount of ESSENTIAL Kneeded to supply the same amount of nutrients is $0.40 - $0.50 per day. No matter how you look at this, Tribute ESSENTIAL K is THE MOST COST EFFECTIVE PRODUCT to feed your horse!!

Significant numbers of today’s horses are kept in stalls with little, if any, free-exercise. It is quite common for these horses to receive minimal quantities of concentrate (grain). Most concentrates on the market today are designed to be fed at 0.5 – 1.0 pounds per hundred pounds of body weight (6 – 11 pounds per day for 1,100 pound horse). Underfeeding these concentrates can result in low intakes of critical nutrients.
Underfeeding a concentrate designed to be fed at higher intake levels compared to feeding a well-designed concentrate designed to be fed at low intake levels can result in:

  • feeding more calories and SIGNIFICANTLY more starch
  • providing much less and poorer quality protein
  • feeding SIGNIFICANTLY lower levels of vitamins and minerals

SOLUTION: For horse where low intake, low calorie, low sugar/starch is desired without sacrificing the other essential nutrients, feed Tribute Equine Nutrition’s ESSENTIAL K!

D.J. Burke, Ph.D.