Natural & Human Resources Grazing Management Decisions Community Response Climate Topography Veg. Community Wildlife Mgmt. Philosophy & Goals Livestock Species cattle, sheep, goats or horses Stocking Rate how many animals Grazing System season of grazing season of rest duration of grazing 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: Number of Animals (How Many?) Type of Animal (What?) Time of Grazing (When?) Duration or Length of Grazing (How Long?)
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 and 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 3 elements: 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:
AUE#/AU Cow = 1 1 Horse =1.8.56 Yearling Steer =.75 1.3 Sheep=.2 5 Jackrabbit =.02 50 Animal Unit Equivalent (AUE) = A conversion factor reflecting the # of AU in an average animal Animal Unit (AU) 1,000 pounds of grazing animal … ruminant
Forage Demand of Animal Ruminants Eat 2.5% of body weight/day in dry matter of forage. Cattle, sheep, goats Deer, elk, bighorn sheep, moose, etc. Hind-Gut Fermentors Eat 3.5% 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 How many pounds is this? AU = 1,000 pound of ruminant grazing animal Ruminants eat 2.5% of body weight each day 30 days in a month 1,000 lb ×2.5% ×30 days = 750 lbs of forage
Basis for Stocking Rates Proper stocking based on maintaining sufficient plant residue for: Maintain soil condition Reduce erosion Add organic matter Photosynthetic material to provide carbohydrates for recover Forage for other animals in ecosystem
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 Research shows that an amount of biomass can be removed each year and the plant can still regrow and sustain itself from year to year. These sustainable levels of utilization are called Proper Use Factors
% Grass Plan Removed% Root Growth Reduction 10%0% 20%0% 30%0% 40%0% 50%2-4% 60%50% 70%78% 80%100% 90%100% http://forestandrange.org/modules/livestockwildlife/edu/Presentation6.ppt Basis for Allowable Use or Recommended Use Level Total Forage × Recommended Use = Usable Forage Supply
Heavy use Overgrazing Overgrazing = repeated heavy grazing such that damage to the plant community occurs. 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 Healthy soil. Slows weedy plant invasion. Improves drought resistance. Improves condition of degraded land.
Animal Production standpoint Proper Stocking Rate?
Stocking rate affects cattle gains: Production per animal
Stocking rate affects cattle gains: Production per animal Competition for existing forage High quality forage reduced and animals need to each lower quality plants Animals need to work harder and travel farther for forage Increased stress and interaction with other animals can increase disease
Stocking rate affects total production: Production per acre
Proper stocking rate? maximum per animal maximum per acre
Proper stocking rate? maximum per animal maximum per acre Optimal Stocking Rate – between max/animal and max/acre
For Livestock Production: Set Stocking Rates At or Below Carrying Capacity Desirable production per animal Optimal production of animals per acre What is Desirable or Optimal depends on the managers goals and objectives.
How do you set stocking rate? Balance supply with demand Simple Four–Step Method
4-step or Forage Demand Method 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: When you have no stocking information from previous years To estimate carrying capacity in biological surveys or land appraisal When considering changes in kind or class of animals
Establish stocking rate based on: 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: Range Trend = changes in plant composition or rangeland health over time
Grazing Principles Which animal -Animal Species & Class How may animals –Stocking Rate When to grazing or not graze -Grazing System Match number and type of animal to the rangeland vegetation, topography and climate