Section 4 - Manure Production

You will need to download the Manure Production worksheet and fill it out. You may also want to download the Solid Manure Production table, or else read it online below. From your operation, you will need to know the type and number of animals you manage, how long they are on your property, and estimate their average weight while there.

• Calculating manure production
• Solid Manure Production table
• Other solid wastes to consider
• Process wastewater generation

Calculating Manure Production

To calculate manure production by a herd, we need to know:

1. Number of livestock in each category (see Solid Manure Production table for categories).
2. Average length of time on site for each category

-- OR the average number of head present year-round IF the number of animals in each category does not fluctuate much within a year.
3. Incoming and outgoing weight of livestock in each category

Step 1: Calculate average animal weight

(Incoming wt + outgoing wt) ÷ 2

Example: Frank's Feedlot has 2500 head on average year-round. The cattle come in weighing 500 lb. each and leave weighing 1200 lb. each.  They are fed a grain diet. (500 + 1200) ÷ 2 = 850 lb./head

Step 2. Get table value for appropriate livestock category

The Solid Manure Production table contains average manure production values (lb manure per day per 1000 pounds of animal) and moisture contents found in animal manures collected from Colorado feedlots. Example: Beef feeder, high-energy diet.
8.7 lb./day/1000 lb. of animal

Step 3. Calculate manure production

A. Multiply table value by average animal weight (from Step 1) divided by 1000.

Ex.: 8.7 lb./day/1000 lb. of animal x 850 lb. average wt. = 7.4 lb. manure per day per animal

B. Multiply by the number of days on feed/year.

Ex.: 7.4 lb. manure/day x 365 days/year = 2,700 lb. manure/year/head

C. Multiply by the number of head fed/year

Ex.: 2,700 lb. manure/year x 2500 head = 6,750,000 lb. manure/year/herd

D. Convert lb. to tons by dividing by 2,000.

Ex.: 6,750.000 lb. manure/year/herd ÷ 2,000 lb./ton = 3,375 tons manure per year Example summary: Frank's Feedlot has 2500 head on average year-round.  Manure production per year from the feeder cattle operation is 3,375 tons.

If Frank's Feedlot has other types of cattle, or other kinds of animals, they would need to do these calculations for each group.

Solid Manure Production (Use for Step 2)

Solid Manure Production - Beef

Animal Type	Production  (lb/day/1,000 lb of animal)	Moisture Content (% at time of spreading)
Feeder, yearling (750 - 1100 lb)
High forage diet	10.1	32%
High energy diet	8.7	32%
450 - 750 lb	11.2	32%
Cow	10.7	32%
Veal	2.8	46%

Solid Manure Production - Poultry

Animal Type	Production  (lb/day/1,000 lb of animal)	Moisture Content (% at time of spreading)
Layer	25.2	40%
Pullet	19.0	40%
Broiler	33.3	40%
Turkey	14.1	40%

 

Solid Manure Production - Horses and Sheep

Animal Type	Production  (lb/day/1,000 lb of animal)	Moisture Content (% at time of spreading)
Horse	14.1	22%
Sheep	14.5	31%

Other Solid Wastes to Consider

Process Wastewater Generation

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