The number of cows an acre in Arkansas can support depends on the land’s ability to produce forage over time. This concept, known as the stocking rate, is defined as the number of animals carried on a specific area of land for a defined period. Determining the correct rate is paramount for the economic sustainability of a cattle operation and the ecological health of the pasture. A sustainable rate ensures that animal demand does not exceed the land’s capacity, preserving forage availability long term.
Defining the Unit of Measurement
To accurately calculate how many animals a pasture can support, agricultural experts use standardized terminology. The most fundamental measure is the Animal Unit (AU), defined as a 1,000-pound mature cow, with or without a suckling calf. This unit is based on the animal’s forage consumption, estimated at approximately 26 pounds of dry matter per day.
The Animal Unit Month (AUM) represents the total forage needed to sustain one AU for one month, equaling about 780 pounds of dry forage. Using AUs and AUMs allows producers to compare the forage requirements of different livestock classes, such as bulls or growing calves. This calculation ensures the actual stocking rate matches the land’s capacity for sustainable use.
Key Ecological Factors Influencing Stocking Rates in Arkansas
The carrying capacity of land in Arkansas is determined by environmental variables that dictate the amount of available forage. The state’s geography presents a wide variety of soil types, which influence grass growth. For instance, northern Ozark Plateau soils differ significantly from the rich Delta soils in the east and the Gulf Coastal Plain soils in the south.
Rainfall is generally abundant, but the timing of precipitation and the threat of summer drought create seasonal challenges for forage availability. Dominant forage species also vary regionally. Cool-season grasses like tall fescue are prevalent in the northern and western parts of the state. Warm-season grasses such as bermudagrass and bahiagrass are more common in the southern counties, thriving in hot summer months. Matching the stocking rate to the specific forage type and its growth cycle is necessary to avoid overgrazing.
Stocking Rate Guidelines by Arkansas Region
Stocking rate guidelines vary widely across Arkansas, reflecting the distinct ecological zones and the types of forage grown. In the Ozark Plateau and Ouachita Mountain regions, cool-season grasses like fescue are dominant. Average stocking rates for cow-calf pairs often fall in the range of 3 to 5 acres per Animal Unit (AU) for year-round grazing, assuming a traditional, continuously grazed system.
The Coastal Plain region in the south, characterized by warm-season bermudagrass, supports a higher density due to high summer production potential. Moderate stocking rates here are often around 2.0 acres per AU. Intensive management can push this to as low as 1.0 acre per AU on highly improved pasture.
Some smaller operations in the Ozark Highlands report rates ranging from 2.2 to 5.3 acres per bred cow, demonstrating significant variability based on management intensity. The Delta region features less dedicated pastureland, as fertile soils are often converted to row crops. However, available forage is typically highly productive, similar to the Coastal Plain’s improved pastures.
Optimizing Land Use Through Management Practices
Cattle producers can implement management strategies to increase the number of cows an acre can sustainably support beyond the land’s natural ecology. A key technique is rotational or controlled grazing, which involves dividing a pasture into smaller paddocks and moving the cattle frequently. This practice significantly increases the utilization of available forage, often rising from 30-40% in continuous grazing systems to 60-75% or more.
Strategic forage management, such as stockpiling, also allows for a higher stocking rate by extending the grazing season and reducing the need for hay. This involves setting aside and fertilizing a portion of bermudagrass or fescue in the late summer or fall for winter grazing. Additionally, interseeding cool-season annuals like wheat or annual ryegrass into warm-season perennial pastures provides high-quality forage during the spring and fall. Implementing these practices can significantly reduce the typical 135-day hay feeding period for Arkansas producers, improving efficiency.