1. Grazing Management: Systems

2. Grazing Systems? Why would you want to use a grazing system?
What do you expect from your grazing system?

3. Grazing Systems Objectives
Vegetation Considerations
Deferment promotes plant succession
Increase desirable species
Reduce and improve sacrifice areas
Improve forage harvest efficiency
Reduce animal selectivity
Grazing systems do not change forage preferences
Integrate range improvement practices:
Brush control
Prescribed burning
Seeding

4. Grazing Systems Objectives
Animal Considerations
Animal production per head and per acre
Many rangeland grazing systems will reduce animal performance
Improve animal management and care
Supplemental feeding
Health care
Artificial insemination

5. Grazing Systems Objectives
Economic Considerations
Reduce costs
Facilities such as watering points and handling equipment
Variable inputs, especially labor
Management considerations
Facilitate application of improved management

6. Definitions for grazing systems
Stocking density – The animal density per unit land area at one point in time.
Stocking rate – The total animal demand per unit land area for during a forage year.
Grazing pressure – The ratio of forage demand to forage available at any point in time.
Cumulative grazing pressure – The ratio between the total forage demand and forage available for the entire forage year.

7. The Goal and Challenge
Increasing harvest efficiency can increase animal production
Deferment promotes range improvement through plant succession
Deferment reduces harvest efficiency

8. Designing Grazing Systems
Considerations of grazing frequency and grazing intensity when designing grazing systems

9. Relationship (linear) between average annual precipitation and recommended proper stocking rate at locations from Sonora, TX to Manyberries, Canada

10. Generalized animal production responses to stocking rate

11. Stocking Rate Considerations
Higher stocking rates produce higher gains per acre when:
Precipitation is above average
Animals receive supplemental feed
Continuous stocking may increase risk during droughts because of:
Need to destock when beef prices are low
Need for costly supplements (lack forage)
Long-term reduction in perennial grasses

12. Three concepts for carrying capacity
Agronomic-livestock production
Focus on Animal Production
Wildlife-animal population equilibrium
Focus on maximum animal numbers
Rangeland management-sustainable use
Focus maximizing animal production while sustaining rangeland productivity
(Kothmann and Hinnant, unpublished)

13. Types of Grazing Systems
Continuous (Yearlong or seasonal)
Rotation Grazing Systems
Deferred Rotation
Merrill 3-Herd/4-Pasture System (DR type)
Rest-Rotation Grazing
High Intensity-Low Frequency (HILF) System
Short-Duration Grazing

14. Rotational Grazing Systems
Purposes include:
Relatively short grazed & non-grazing periods
Control timing of grazing
Reduce area selectivity
In humid grasslands and tame pastures:
Can increase animal production/acre (not per animal) through more uniform use of plants

15. Deferred Rotation Emphasizes deferment of forage use
Grazing area divided into at least two pastures allowing non-grazing for part of a year
Generally use 2, 3, or 4 pastures
Merrill 4-pasture 3-herd is an example

17. Merrill System
This is a deferred rotation system that emphasizes cyclic deferment of grazing
Pasture and rotation characteristics:
Area divided into 4 pastures, used by 3 herds
Each pasture grazed 12 mo, “deferred” for 4 mo
Each pasture is deferred once in each season during a 4-year cycle
Useful where yearlong grazing is practiced
Winter rest allows soil recovery although forage may not be actively growing

18. Rest-Rotation Grazing
Emphasizes a full year’s rest for part of the grazing area
Used in mountainous areas in western US
Pasture and rotation characteristics:
3-5 pastures per herd
One pasture receives 12-months rest
Grazing pressure in others increases

19. Rest-Rotation Grazing
Advantages:
Low SR and non-grazing can improve vegetation
Low livestock numbers can provide multiple-use advantages with more forage allocated for wildlife & watershed
Disadvantages:
Generally reduces animal production per head and per acre
If SR not reduced significantly, intensive grazing for full grazing season may damage rangeland

20. High Intensity-Low Frequency
HILF grazing emphasizes improvement of range condition thru use of high grazing pressure to increase uniformity of forage use with sufficient non-grazing time for plants to regrow following grazing
Pasture and rotation characteristics:
3+ pastures
Grazing periods of at least 14 days
Non-use periods of at least 60 days

21. High Intensity-Low Frequency
Advantage:
Minimizes competitive advantage for less preferred plants because animals are forced to be less selective
Disadvantages:
Individual animal performance decreases when animals are forced to eat mature, unpalatable forage
Requires reduction in stocking rate (similar to Rest Rotation)

22. Short-Duration Grazing
SDG emphasizes increased grazing pressure for short periods to minimize excessive plant defoliation and to allow rapid regrowth of grazed plants
Pasture and rotation characteristics:
 8 paddocks/herd, each with equal forage supply
5 days or less grazing period (shorter during active plant growth periods than dormant period)
Non-grazing periods < 4-6 weeks

23. Short-Duration Grazing
Advantage:
SDG may improve diet quality because maturation of forage is delayed by repeated defoliation
Centralized watering/handling facilities (wagon-wheel) that can improve livestock management and reduce labor and facilities expenses
Disadvantage:
Lots of fencing and high fencing cost
Animal trails in long narrow paddocks
< 60-day growing period in arid areas diminishes positive effects of repeated defoliation/rest

27. Custom design your grazing system
What are your vegetation management goals?
What are your animal production & management goals?
What are your management and economic constraints?