This document discusses four key principles of grazing management: stocking rate, season of grazing, distribution of grazing across the landscape, and matching animal kinds and classes to rangeland vegetation. It provides details on monitoring grazing intensity using methods like the key species approach and key area monitoring. Factors that influence grazing distribution like distance from water, vegetation type, topography, and improvements to distribution through prescribed burning and infrastructure are also examined. The document emphasizes matching the sustainable level of forage use to rangeland productivity.

1. Grazing Management
Principles for Rangelands
Mort Kothmann
Texas A&M University

2. Four Basic Principles of
Grazing Management
►Stocking rate
►Season of grazing
►Distribution of grazing across landscape
►Match kinds and classes with the rangeland
vegetation, topography and climate

3. Grazing Management Concepts
Basic tenets of grazing management
►Grazing intensity (degree of use)
 Light – moderate – heavy – extreme
►Methods for monitoring degree of use
 Key area method (Key species)

4. Grazing Intensity
► A certain amount of
plant biomass must
remain to maintain
to assure health of
animals, plants and
soil
 Herbivore diet
 Plant vigor and
reproduction
 Soil stability

5. Grazing Intensity
►As annual precipitation declines, sustainable
level of forage utilization generally
decreases
 Sustainable intensity of grazing is directly
related to availability of water and soil nutrients
 Greater resource availability increases
proportional allocation to shoot relative to root

6. Grazing Intensity
►Recommended levels of use based on field
estimates and (harvest efficiencies)
 Ryegrass (water & N unlimited) 75% (70-80%)
 Coastal Bermudagrass pasture 50% (40-60%)
 Humid tall grassland 40-50% (20-30%)
 Semiarid grasslands: 20-30% (15-20%)
 Arid SW & Intermountain West: 15-20% (10-15%)
The more arid the land, the lower the sustainable
intensity of use.

7. Monitoring Range Utilization
►Key Species Method for monitoring use
 Monitor utilization of 1-3 key species that are
abundant, productive, and palatable (decreasers
or increasers) rather than monitor many species
 Assumption: use of entire range is optimal
when use of key species is optimal:
►Key species are moderately used – 30-40 %
►Secondary species are lightly used – 10-25 %
►“Ice-cream” plants may be overused – >40 %

8. Monitoring Range Utilization
► Key Area method for monitoring range use
 Monitor an area that is “representative” of overall range
condition, trend, and degree of seasonal use
 No rangeland is uniformly used – some “sacrifice” areas
will occur due to area selectivity
►Heavy use – Clipped or mowed appearance
 >50 % of fair or poor forage plants used
►Moderate Use
 50 % of good or fair forage plants used
►Light use
 Only choice plants used

9. Monitoring Range Utilization
►Key Area method for monitoring range use
 Optimal stubble height in key areas following
grazing vary:
►Tall-grasses
 30-35 cm (12-14 inches)
►Mid-grasses
 15-20 cm (6-8 inches)
►Short-grasses
 5-8 cm (2-3 inches)

10. TGM for Monitoring Degree of Use
►Using the Demand Day (DD) as a measure
of animal production and maintenance from
the pasture.
 Energy required for maintenance and growth is
estimated from animal weights and expressed
as DD.
 Productivity of the pastures is estimated from
observed animal production and degree of use
on the pasture.

11. Season of Use
► Yearlong
 Used primarily in tropical & sub-tropical climates
► Seasonal
 Temperate to cold climates
 Tame pastures
► Rotational
 Grazing Systems (This will be covered in a separate
presentation.)

12. Length of
Grazing Season vs Growing Season
► Rangelands– Grazing season is generally longer
than the growing season. This requires stockpiling
forage for use during the non-growing season.
This frequently involves very light use during the
peak growing season.
► Tame Pasture– Grazing season is matched with
the growing season to harvest forage near
maximum quality. Stockpiling forage usually
involves shortening the grazing period during
active growth.

13. Timing of Grazing
► Effect of grazing varies according to:
 Season of use -- Plants are more resistant to intense
herbivory during dormancy than in active growth.
 Phenological stage of plant -- Defoliation in spring
when plants start growth may be less harmful than in
fall when plants are flowering and maturing.
 Opportunity for regrowth – Will plants be able to
produce new leaves and develop strong root systems
prior to entering dormancy following defoliation?

14. Grazing Distribution:
Animal Selectivity
►Area distribution
 Landscape
 Patch
 Feeding station
►Species selective grazing
►Plant part selective grazing
 Live or dead
 Leaf of stem

15. Area Selection
►Factors affecting area selection include:
 Distance from Water
 Vegetation Type
 Topography (Slope)
 Range Site (Soils)
 Weather
 Animal pests such as flies
 Kind & class of animal
 Management practices such as supplementation

16. Distance from Water
►Recommended distances between watering
points vary according to terrain, species of
animal, and breed of livestock
►General recommendations:
 Rough country: ≈ 0.5-mile max
 Rolling country: 1.0-mile max
 Flat sandy country: ≈ 1.5-mile max
 Flat country ≈ 2.0-mile max

17. Vegetation Type
►Herbivores select areas with vegetation that
best meets their nutritional needs
 Bulk grazers prefer open grasslands
►Cattle, Buffalo, White rhinos
 Browsers prefer wooded areas
►Mule deer, Giraffes, Black rhinos

18. Topography
Cattle
Horses
Deer
Bighorn
Percent Slope
Percent
of
Observations
10
20
30
40
50
60
70
10 20 30 40 50 60 70 80+
Figure 10.2 Relationship of slope gradient to the percentage of
observations of cattle, feral horses, deer, and bighorn sheep.
(From Ganskopp and Vavra 1987. Reprinted with permission.)

19. Improving Livestock Distribution
►Provide supplemental feeds/mineral licks
 Cattle move from water to grazing to salt:
►Change location of salt-mineral licks
►Place salt away from water in areas that grazing
animals are avoiding
►Grazing systems that reduce pasture size
and significantly increase animal density
may improve livestock grazing distribution.

20. Improving Livestock Distribution
►Prescribed burning
 Removal of previous years’ growth
►Greater access to new plant growth
 Early spring fires can
►Increase soil temperature
►Initiate growth
►Improve forage quality
►Encourage earlier grazing

21. Improving Livestock Distribution
►Adjust kind/class of livestock
 Changing animal species can improve livestock
distribution depending on:
►Vegetation composition
►Water distribution
►Topography
 Because of non-uniform plant composition, multi-
species animal production systems can increase:
►Herbivore distribution
►Vegetation use
►Animal production

22. Improving Livestock Distribution
►Fencing can be used to control:
 Area selective grazing
 Season of use
 Rotational grazing systems
 Use of high-value forages such as hay crops
 Movement of wildlife

23. Livestock Distribution
►Negative Aspects of Fencing
 Cost prohibitive where productivity is low
 Electric fences are less costly to construct
than standard barbed wire but more
expensive to maintain
 Restrict movement of some wild species
 High-fencing to control game species

24. Kind & Class of Animal
► Kind of animal (species)
 Cattle, sheep, goat, horse, wildlife species
► Class of animal (age, sex, physiological status)
 Reproductive -- pregnant or open
 Age -- mature or young
 Lactating or dry
► Adaptation to climate and forage quality
 Breed of animal
 Genetic potential for growth and lactation

25. Choice of Kind & Class of Animals
►Match animal genetics with forage quality
►Match the grazer with the landscape and
the kinds of vegetation