Bulletin #2263, How Maine Farmers Can Determine if They Have Enough Hay and Forage for the Winter

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By Richard Kersbergen, Extension Professor, University of Maine Cooperative Extension.

For information about UMaine Extension programs and resources, visit extension.umaine.edu.
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Round hay balesFrequently, we experience challenging years in terms of hay harvest and silage production. Not only might yields be low, the quality of the forage may also be of poor nutritional quality. Many times in the fall, livestock producers will ask, “Will I have enough forage this year for my livestock?” It is always better to know now than later. This factsheet will help you find the answer to that question.

First, you need to determine how much forage you will need this year. This depends on the type of livestock you keep, number of head, age, weight, level of production, level of work, etc. Then you need to determine how much forage you have on hand. You may also need to know the volume of your storage and the nutrient density of the forage.

Determine How Much You Need

Many producers have a good estimate of their daily feed needs from what they feed daily to their animals. If not, some of these resources may be useful. Table 1 outlines what animals of various species and productive status are in terms of animal units. One animal “unit” equals 1,000 pounds of body weight. Remember, that this is just one factor in an animal’s nutritional needs. The amount of dry matter (DM) an animal will eat will depend on its body weight, quality of the feed, and class of stock. It is important to calculate the average daily intake to ensure that you are feeding the correct amount by weight or that the animal is able to obtain enough nutrients from a certain feed determined by intake limits.

Table 1. Animal Units

It is assumed that one mature cow represents an animal unit or 1,000 pounds. The comparative feed consumption of other age groups or species of animals determines the proportion of an animal unit that they represent.

Source: Feeds and Nutrition, M.E. Ensminger, J.E. Oldfield, W.W. Heinemann, Ensminger Publishing Co., 1990.
Type of Livestock Animal Units
Beef Cattle:
1,000 lbs. Cow, with or without unweaned calf at side 1.0
Heifer, 2 years old or older 1.0
Bull, 2 years old or older 1.3
Young Cattle, 1 to 2 years 0.8
Weaned calves to yearling 0.6
Draft Horse 1.7
Light Horse, mature 1.3
Light Horse, yearling 1.0
Weanling colt or filly 0.75
5 Mature ewes, with or without lambs at side 1.0
5 Rams, 2 years old or older 1.3
5 Yearlings 0.8
5 Weaned lambs or yearlings 0.6

Cattle and sheep generally consume between 2-3% of their live weight in DM daily. Horses would consume about 1.2-2% of their body weight. This would include any grain you may be feeding as well. Animals that are in a more productive stage in life (i.e. ewes with 2 nursing lambs or horses that are doing work or active) will have higher nutrient needs and higher dry matter intakes.

Table 2 details pounds of hay per day/month/number of bales per month assuming an intake of about 2% of body weight per animal unit (AU).

Table 2. Approximate Amount of Hay Needed By Animal Unit at 2% of BW Intake

Animal Unit
Pounds of Hay
per day
Pounds of Hay
per month
Number of 40-pound bales
per month
1 20 600 15
2 40 1200 30
3 60 1800 45

When planning forage needs, an additional 5-15% loss (waste) in forage dry matter will occur during storage and feeding depending on feeding and forage management.

If you are feeding or buying round bale silage as an alternative to dry hay, it is important to know the dry matter of that feed. As an example, if you are buying a 1,200-pound round bale of silage at 40% dry matter, you are actually buying 480 pounds of dry matter or 533 pounds of Hay Equivalent (HE) since hay is about 90% DM.

(1,200 pounds of baleage X 40% or 0.40) = 480 pounds

If you want to compare that to Hay Equivalent (HE), you would then divide by the average dry matter of hay (90%).

(480 pounds dry matter / 90% or 0.90) = 533 pounds of Hay Equivalent.

Determine How Much You Have

It is a good practice to weigh the feed packages you are using or intend to buy. Square bales can range from 30-60 pounds and round bales can be quite different based on the size and density of the bale. Table 3 gives you some estimate of the value of round bales of hay as compared to square. If round bales are stored outside, the waste can be significant (11-44%), depending on how they were stored and how long they were exposed to the weather.

Table 3. Round Bale vs. Square Bale

Note: Losses due to weathering can vary from 11% to 44% for round bales left outside
Size of Round Bale Equivalent Number of Square Bales
40 lb. Bale 50 lb. Bale 60 lb. Bale
4’ Diameter (600 lb.) 15 12 10
5’ Diameter (1,000 lb.) 25 20 16-2/3
6’ Diameter (1,400 lb.) 35 28 23 -1/3

Finally, the quality of the forage you buy is critical to how much you need to feed to meet your animal’s nutritional needs. Testing forages before you buy can help you determine the price you should pay. Allocating your best forage for when your animals need the highest plane of nutrition (ex. Ewes nursing lambs) is also critical. For information on testing your feed, this video may provide some guidance.

VIDEO: How To Test Forage Quality (YouTube)

Not Enough Forage?


  • Purchase More Forage: UMaine Extension maintains a Hay Directory that lists farms that have hay available. Farmers also advertise in traditional and social media.
  • Feed More Grain and Reduce Forage: Be sure to calculate the cost by nutrients available. Ruminants and horses need to have at least 50% of their diets on a dry matter basis as forage for digestive health.
  • Reduce Herd or Flock Size:  To match your forage availability.

Information in this publication is provided purely for educational purposes. No responsibility is assumed for any problems associated with the use of products or services mentioned. No endorsement of products or companies is intended, nor is criticism of unnamed products or companies implied.

© 2020

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