Topics : Pastures : 4 Steps to Rotational Grazing
4 Steps to Rotational Grazing
Additional pasture information via the Forage Information System (FIS)
Step 2: Estimate how many acres will be needed throughout the grazing season.
Estimating the number of acres required to pasture a herd or flock depends not only on the feed requirements of the animals but also on the available forage produced. Pasture growth is dependent upon plant species, soil characteristics, topography, fertilization, temperature and soil moisture. Because of the variability in pasture growth, we can only estimate the number of acres required for grazing animals.
To estimate how much pasture a herd or flock will need, first calculate the total AU of the herd (Step 1). Second estimate how many acres each AU will need during each month of the grazing season (Table 2). For example, if the herd will be grazing medium producing Kentucky bluegrass and white clover pasture in June, then approximately 1.3 acres will be needed to support each AU. The same herd grazing medium producing orchard grass and white clover pasture would only need 0.7 acres for each AU.
The herd (from Step 1, we know the herd contains 50 AU) will be grazing medium producing orchard grass and white clover pasture.
May: (0.7 acres/AU) X 50 AU = 35 acres
June: (0.7 acres/AU) X 50 AU = 35 acres
July: (1.2 acres/AU) X 50 AU = 60 acres
Aug.: (1.2 acres/AU) X 50 AU = 60 acres
Sept.: (1.2 acres/AU) X 50 AU = 60 acres
Oct.: (6.2 acres/AU) X 50 AU = 310 acres
For the example herd, 60 acres will be sufficient for much of the year. However, there will be excess forage in the spring and the herd will need to receive supplemental forage in October. During this deficit period in the fall, stockpiled tall fescue or brassicas could be utilized.