Transcript Forages

Forages
• Forage – the edible parts of plants, other
than separated grain, that can provide
feed for grazing animals, or that can be
harvested for feeding.
Forage Classification:
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A. Grass –
B. Legume –
C. Annual D. Biennial E. Perennial –
F. Warm Season Plants –
G. Cool Season Plants-
Typical Growth of a Cool Season
Perennial Grass:
• Example – Tall Fescue (Festuca aurndenacia)
• Fall of 2002 – plant a new stand or have existing stand that is
vegetative (no stems). Plant stores carbohydrates for winter,
new tillers are initiated.
• Winter 2002-2003 – low temperatures vernalization occurs
• Spring 2003- leaf growth resumes on tillers, temperature
rises, days lengthen. March internodes lengthen to form
stems and flowers emerge. Flowering tillers die
• Spring-Summer 2003 – defoliation by grazing or hay cutting
• Summer 2003 – regrowth all vegetative
• Fall 2003 – may have some late flowering tillers
Typical Growth of Warm Season
Grasses:
• Example- Bermudagrass (Cyanodon
dactylon)
• Establish form seed or sprigs in April – June.
• Vegetative growth occurs with production of
stolons, rhizomes, and aerial stems.
• Flowers are produced but are sterile in most
hybrids
• Start storing carbohydrates mid-August and
beginning of September.
Typical Growth of Alfalfa:
• Alfalfa (Medicago sativa)
• Establish in fall (August – early September) or
spring (February – April)
• Alfalfa will remain vegetative until 1 – 3 ft. tall
• Stages: Vegetative – no flower buds present
» Bud – no flowers open, buds at leaf axis
» First Flower – first flower open in field
» Flowering - %, number of stems with flowers / 100
stems.
» Pod development – green pods
» Ripe seed – mature brown pods.
• Red Clover growth is similar to alfalfa
• White clover – does not produce upright
stems
Grazing Management
• Managing pastures to achieve maximum light
interception and harvest.
– Animal unit (AU) – 1000 lb animal
– Animal unit day – 1 AU x 1 day
– AUM per acre – the (# of AU’s x # months)
# of Acres grazed
-Available forage
-Forage Allowance
-Stocking rate – AU/Acre
-Carrying Capacity – opt. stocking rate over time
-Stocking density – number of animals/acre of paddock
What is more important than the
type of grazing system:
• 1. Maintaining desirable forage
composition.
• Control weeds
• 2. Maintaining optimum forage availability
• Soil nutrients
• No overgrazing or undergrazing
• 3. Good utilization
• Stock heavy enough to minimize waste
• Prevent stemmy growth
• Stockpile excess
Pasture Growth Depends on:
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Photosynthetic efficiency
High sustained growth rate
Low rate of leaf aging
Maintenance of vigorous tillers
Effects of Grazing Animals on
Pasture:
• 1. Defoliation – overgrazing and
undergrazing.
• 2. Treading
• 3. Excretion
How Do Animals Graze?
• Sheep – nibble more efficiently harvest,
more selectively
• Cattle – wraps tongue around plant and
tears it.
• Horses – highly selective, prefer close
grazed forage.
Factors Affecting Optimum
Stocking Rate:
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Forage production
Accessibility of forage to animals
Nutritive value of forage
Species composition
Season variations in forage production
Economic considerations
Managing the Canopy:
• 1. Undergrazing – produces too much
canopy
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Shades low growing species –clovers, lespedeza
Produces stems of low quality
Old leaves die form excessive shade
Trampling of grazable forage
Results: Legumes are driven out, no free N.
Free solar energy goes to soil not the animal.
• 2. Overgrazing: Frequent and excessive
canopy removal.
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Loss of desired species – legumes, quality grasses
Slow regrowth – lowers carrying capacity
Poor root growth - reduces carrying capacity
Boom and bust growth
Soil bakes in summer, water evaporates, runs off
Grazing Management Tools:
• 1. Continuous stocking – one open field, not
subdivided. Forage is grazed while it is growing
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Stocking rate = stocking density
Selective grazing results – unpalatable weeds
Patchy grazing
Overgrazing – sometime during year
Undergrazing- sometime during year
High production/animal and low production/acre
Must use a grazing tolerant species (Bermudagrass and E+
Tall fescue)
• 2. Controlled Grazing – Management
intensive – make animals graze what,
when, and where, and how much you want
them to graze.
• Can be achieved by altering:
– Stocking rate
– Rate of rotation – grass height should not be greater than
6-8 inches and no shorter than 2 inches.
Grazing tolerance of plants:
• 1. Plant a grazing tolerant species:
• Bermudagrass, E+ tall fescue, Kentucky
bluegrass, White Clover
• 2. Intermediate tolerance:
• Caucasian bluestem, Alfagraze alfalfa, Marion
lespedeza, Smooth Bromegrass, Orchardgrass,
Small grains
• 3. Low tolerance: plants need rest
between rotations.
Flexibility can be used in any
grazing situation by:
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1. Alter # of cattle per paddock
2. Alter # of paddocks
3. Speed rotation through paddocks
4. Shift herd to another type of forage
(CSG  WSG  CSG).
• 5. There is no flexibility during drought or
winter.