top of page
  • Writer's pictureMD-DE Forage Council

Grazing Math

by Brian Campbell, NRCS Grazing Specialist


There are helpful calculations available to help farmers design a new pasture system or avoid damaging existing pastures by not overstocking, overgrazing, or under-sizing. Grazing math can be used to answer questions like:

· How many animals can my pasture/paddock support?

· How many days will my pasture/paddock last?

· How many acres should my pasture/paddock be?

The calculations use some assumptions about (1) how much forage your livestock need to meet their daily dry-matter needs – based on the class of livestock; (2) how efficiently those animals can utilize the pasture – based on how intensively livestock are rotated through paddocks (i.e. pasture subdivisions); and (3) how much forage the pasture has available – based on pasture height and density:

Once you find the appropriate numbers for your situation, input them into the calculations below. Remember, when you enter percentages into a calculator, that they often need inputted as decimals – for example, 3% as 0.03. You will probably only need to use one of the calculations at a time because you will often only be changing one variable at a time: the number of animals on a pasture/paddock, the number of days your animals remain on a pasture/paddock, or the size of a pasture/paddock.

Our example calculations will assume the following scenario: five retired horses averaging 1,100 pounds graze a pasture of mixed cool-season forages; these horses are expected to meet their dry-matter needs on pasture alone (without supplemental feed) and are moved to a new paddock once a week.

If you would like assistance in improving your pasture management, please contact your local USDA Service Center.

USDA is an equal opportunity provider, employer, and lender. To file a complaint of discrimination, write: USDA, Office of the Assistant Secretary for Civil Rights, Office of Adjudication, 1400 Independence Ave., SW, Washington, D.C. 20250-9410 or call 866-632-9992 (toll-free customer service), 800-877-8339 (local or federal relay), 866-377-8642 (relay voice users).

Recent Posts

See All

Spring Forage Nitrogen Management

by Amy Shober, Sydney Riggi, and Jarrod Miller; University of Delaware Extension Early Spring Nitrogen Application Strategies Nutrient loss potential is still high during the late winter and early spr

Summer Grazing Management

by Amanda Grev, Pasture Management Specialist As we move into the traditionally driest, hottest days of summer, we can expect stretches of dry weather and hot temperatures. During this time of year, g


bottom of page