grazing management: systems. grazing systems? why would you want to use a grazing system? what do...

Grazing Management:

Systems

Grazing Systems?

Why would you want to use a grazing system?

What do you expect from your grazing system?

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

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

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

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.

The Goal and Challenge Increasing harvest efficiency can

increase animal production Deferment promotes range

improvement through plant succession Deferment reduces harvest efficiency

Designing Grazing Systems Considerations of grazing frequency and

grazing intensity when designing grazing systems

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

Generalized animal production responses to stocking rate

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

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)

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

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

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

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

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

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

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

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)

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

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

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?