Healthy Landscapes: How To Manage Manure

The bigger picture - how much manure is produced, how much land is available

- Land / animal connection: animal units and stocking rates.

Photo courtesy of University of New Hampshire Cooperative Extension.

How much an animal weighs directly relates to the amount of feed it requires and the amount of manure it generates. Livestock weight varies depending on the type, breed, gender, age, and function.

Approximate lbs. of solid waste (feces and urine) produced by various types and sizes of livestock – does not include bedding.

Horse (1000 lbs)	50 lbs. manure / day	9 tons / year
Beef Cow (1000 lbs)	63 lbs. manure /day	11.5 tons / year
Dairy Heifer (750 lbs)	64 lbs. manure / day	11.6 tons / year
Pig – grow/finish (220 lbs.)	14 lbs. manure / day	2.5 tons / year
Sheep – lamb (125 lbs.)	5.0 lbs. manure / day	1,825 lbs. / year
Layer Hen (4 lbs.)	0.25 lbs. manure / day	91 lbs. / year

Information derived from the USDA Soil Conservation Service Agricultural Waste Management Field Handbook.

Making the connection between animal numbers and the land needed to support them.

The number of animals that can be supported by the land is based on many factors including the ability to provide feed, safe manure handling and recyling, and access to space, shelter and water.

For planning purposes, a general rule of thumb is that it takes one to two acres of land to support 1 animal unit or 1,000 lbs. of live weight.

This is often referred to as a stocking rate and this general rule of thumb can change throughout the country. In the Northeast Region, generally, it requires 1 to 2 acres of land to support one animal unit. Tell me more about determining animal units.

one 1,000 lb. horse = 1 animal unit
two, 500 lb. ponies = 1 animal unit
one 1,400 lb. dairy cow = 1.4 animal units
one 1,200 lb. beef steer = 1.2 animal units
five 200 lb. pigs = 1 animal unit
eight 125 lb. goats = 1 animal unit
250 layer hens weighing 4 lbs. each = 1 animal unit

Photo courtesy of University of New Hampshire Cooperative Extension.

Many small acreage livestock owners do not have the corresponding land, equipment or time to raise all of the necessary feed and recycle all of the manure generated on-farm. Even if the property has several acres, the land that is available for spreading manure may be limited. What does this mean?

We must purchase feed for our animals.
We are likely to have a surplus of manure and nutrients - we need to take some or all manure away to a place that can use it.
We must take steps to do the best job we can with the land we have available.

Even when land is sufficient, manure, livestock yards, pastures and other livestock activities can harm water resources and animal health if they are not managed properly.

Now that we have a basic idea of our manure production and land available we can consider:

- storing the manure

- composting options

- recycling of manure and compost: on-farm or take it away
Photo courtesy of the Mid-Atlantic Pasture Initiative.

More about determining animal units

To determine the total number of animal units on your farm, simply add up the total live weight that you have in animals and divide by 1,000.

Example: one farm raises 2 horses at 1,200 lbs. each; 1 beef steer at 1,000 lbs.; a dozen layer hens at 4 lbs. each.

2 (1,200 lbs.) + 1,000 lbs. + 12 (4 lbs.) = 3,448 lbs / 1,000 lbs./A.U. =

3.4 animal units

Many of us grow animals from young stock to adult for food or sale. In this case, take an average weight.

Example: we purchase a 65 lb. pig and raise it to 220 lbs. for food or sale. The average weight while on the farm is then:
65 lbs. + 220 lbs. / 2 = 142.5 pounds

142.5 pounds / 1,000 lbs./A.U. = 0.14 animal units

About 7 of these animals would be roughly equivalent to 1 animal unit.