Guidelines for Setting Proper Stocking Rate K Launchbaugh
Guidelines for Setting “Proper” Stocking Rate K. Launchbaugh UDSA-ARS
Natural & Human Resources Climate Topography Veg. Community Grazing Management Decisions Livestock Species • cattle, sheep, goats or horses Stocking Rate • how many animals Wildlife Mgmt. Philosophy & Goals Grazing System • season of grazing • season of rest • duration of grazing Community Response Vegetation Community Livestock Production Wildlife Community Important point: Once grazing management decisions are made, there are continual interactions between livestock, wildlife, & vegetation
Four Grazing Mgmt Factors: o o Which animal? -Animal Species & Class How many animals? -Stocking Rate When to grazing or not graze? -Grazing System Where animals graze? – Grazing Distribution
Carrying Capacity The number of animals that a piece of land can support on a long-term basis without causing damage to the ecosystem. • Land vegetation determine grazing capacity • Expressed as animals/area/year (usually acres per AUM per year) • Land is usually bought and sold on this basis
Stocking Rate The number of animals a land manager places on a piece of land for a specified period of time. • Must include: • Number of animals or Animal Unit • Specific area (acres or hectares) • Specific period of time (days or months) • Most important grazing decision because it affects: • Rangeland health • Economic returns
Animal Unit (AU) 1, 000 pounds of grazing animal … ruminant Cow = Horse = Yearling Steer = Sheep = Jackrabbit = AUE #/AU 1 1 1. 8. 56. 75 1. 3. 2 5. 02 50 Animal Unit Equivalent (AUE) = A conversion factor reflecting the # of AU in an average animal ** See assigned reading from more examples
Forage Demand of Animal Ruminants o o o Eat 2. 5% of body weight/day in dry matter of forage. Cattle, sheep, goats Deer, elk, bighorn sheep, moose, etc. Hind-Gut Fermentors o o o Eat 3. 0% of body weight/day in dry matter of forage. Horses Rabbits and rodents
Animal Unit Month (AUM) Amount of forage an AU will eat in a month n –How many pounds is this?
Animal Unit Month (AUM) Amount of forage an AU will eat in a month n –Grazing ruminant animals eat about 2. 5% body weight per day. – 30 days in month – How much is an AU?
Animal Unit Month (AUM) Amount of forage an AU will eat in a month n –Grazing ruminant animals eat about 2. 5% body weight per day. – 30 days in month – How much is an AUM? Each AU = 1, 000 lbs × 2. 5% = 25 lbs/day AUM= 25 lb * 30 days = 750 lbs
Proper stocking rate? Range Health standpoint
Basis for Stocking Rates � Proper stocking based on maintaining sufficient plant residue for: ◦ ◦ ◦ Plant health/regrowth Wildlife forage Erosion prevention � Set ◦ ◦ stocking rate below carrying capacity To allow for drought To allow for low productivity years
Utilization Guidelines: Based on ecological research % Use of Major Plants 30 -40 40 -50 30 -40 Range Type Sagebrush grasslands Shortgrass prairie Coniferous Forest Oak woodlands
Root Response to Defoliation http: //forestandrange. org/modules/livestockwildlife/edu/Presentation 6. ppt
Importance of roots Remove the Leaves ----- Affect the Roots
Root Responses to Defoliation 50% 70% 90% Level of Removal
Root Responses to Defoliation Basis for “Allowable Use” or “Recommended Use” Levels Total Forage × Recommended Use = Usable Forage Supply
Heavy use ≠ Overgrazing o Overgrazing = repeated heavy grazing such that damage to the plant community occurs o Overstocking = heavy grazing during a specific season such that high levels of utilization are observable. Overstocking does not always lead to Overgrazing
For Rangeland Health: Set Stocking Rates Below Carrying Capacity o o Healthy soil. Slows weedy plant invasion. Improves drought resistance. Improves condition of degraded land.
Proper stocking rate? Animal Production standpoint
Stocking rate affects cattle gains:
Stocking rate affects cattle gains: Production per animal stocking rate Ex c es siv e e at od er M Lo w 120 100 80 60 40 20 0
Stocking rate affects total production: Production per acre stocking rate Ex c es siv e e at od er M Lo w 100 90 80 70 60 50 40 30 20 10 0
Proper stocking rate Bement 1969
For Livestock Production: Set Stocking Rates At or Below Carrying Capacity Desirable production per animal n Optimal production of animals per acre n What is “Desirable” or “Optimal” depends on the manager’s goals and objectives. n
How do you set stocking rate? Balance supply with demand Simple Four–Step Method
4 -step or Forage Demand Method o o Calculate usable forage Adjust for terrain, water, or other constraints Calculate forage demand of animals Calculate stocking rate
4 -step or Forage Demand Method The forage demand method is used: q When you have no stocking information from previous years q To estimate carrying capacity in biological surveys or land appraisal q When considering changes in kind or class of animals
Flexible vs. Constant stocking: n Amount of forage varies from year to year long-term average Flexible - no more than 60% of herd in breeding stock n Constant - herd size that could be sustained if rainfall was 25% below average. n
Establish stocking rate based on: o o o Past experience Current situation Long-range weather forecast Financial goals Etc.
Set a Stocking Rate and Then Monitor! With this method stocking rate is determined by trial and error over years and then monitored by: o Range Trend = changes in plant composition or rangeland health over time
Grazing Principles o o o Which animal -Animal Species & Class How many animals -Stocking Rate When to grazing or not graze -Grazing System Match number and type of animal to the rangeland vegetation, topography and climate
Grazing Capacity Summary o o Use caution when estimating grazing capacity Combine n n n o o Utilization measurements Interpretation of current range condition Knowledge of past and present stocking Monitor! Adjust when needed!
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