Forages Flashcards
Forages are feedstuffs containing greater than _____ crude fiber
18%
Forages make up the first 3 feed classes in the IFNS of feed classification including ________, _________, and _________
- forages fed fresh (pastures, green chop)
- hays and hulls (dry forages)
- silages (forages stored by anaerobic fermentation)
Forages have the (greatest/least) variation in nutrient content of all feedstuffs
greatest
Nutritional value varies according to: (4 things)
- forage species used
- stage of maturity of forage at harvest
- harvest and storage process
- parts actually consumed by animal (leaf vs stem; most digestible vs least digestible)
Forage cell wall (NDF) is the largest determinant of ________
forage intake
Calculation method of Relative Feeding Value
- estimate digestible dry matter (%DDM)
- estimate dry matter intake (DMI)
RFV = (DDM x DMI)/1.29
Cool season grasses (C3 plants) photosynthesize best at _________ (temp.)
65 - 75 degrees F
Cool season grass examples
orchardgrass
timothy
ryegrass
tall fescue
warm season grasses (C4) maximize their photosynthesis at _______ and are ______ more efficient at capturing solar energy than C3 plants
90 - 95 degrees F
40%
warm season grass examples
switchgrass
big bluestem
bermuda grass
factors affecting grass growth rate
day length
temperature
rainfall
grass type (cool vs warm)
general characteristics of grasses
- 10-18% CP on average
- higher in cell wall NDF but lower in lignification of cell wall compared to legumes
- better suited for pastures
- more suitable for repro cycle of beef cattle and sheep
What is bloat?
failure of the eructation process
risk factors of bloat?
lush forages contain proteins that lead to gas bubble formation
treatment and prevention of bloat?
- stimulate chewing
- stomach tube or rumen trocar
- feeding dry hay prior to pasture turnout
legumes do not require ________
nitrogen fertilization -
capable of fixing their own nitrogen from the atmosphere through a symbiotic relationship with nitrogen fixing bacteria
legumes have ______ protein ( ______%) and ______ calcium ( _____%)
high protein (15-25%) high calcium (1.5-2%)
examples of legumes
alfalfa
red clover
white clover
birdsfoot trefoil
legumes don’t graze well because
it causes lodging and bloat problems but can work well in grass-legume mixtures
legumes are lower in cell wall content than grasses BUT cell wall is more highly ______ making the fiber less digestible
lignified
advantages of using mixtures of grasses and legumes
- less N fertilizer is required for grasses
- efficient use of space
- less risk of bloat
disadvantages of using mixtures of grasses and legumes
- variability in nutrient composition
- over time one species predominates
types of pastures
permanent rotational strip rangeland stockpiled
Range Land
land that contains native grasses and shrubs that is suitable for grazing
why is range land not suitable for intensive agriculture
- inadequate rainfall
- inadequate soils
- poor drainage
- poor fertility
- too steep for row crop farming
advantages of permanent pasture
- animals have continuous access
- low labor input
- equivalent to rotational grazing during early system
disadvantages of permanent pasture
- quality is not maintained during the growing season
- animals become very selective
- relatively low stocking rates
Managed Intensive Rotational Grazing (MIRG)
- system where pastures are managed for optimal digestibility and yield to maximize animal productivity per unit land
- involves rotation of animals through paddocks every 21-28 days where animals spend no more than 1-2 days per paddock
advantages of rotational grazing
- maintaining forages in a vegetative state
- maximize animal performance
disadvantages of rotational grazing
requires repeated nitrogen filtration unless legume mixtures are used
strip grazing
- variation on rotational grazing except that a strip of a large field is opened on 12-48 hr intervals
- more efficient use of pasture, less permanent fencing
Green chop
forages that are harvested mechanically, transported to the feed manager and fed fresh
advantage of green chop
reduced weather and field losses as compared to pasture systems
disadvantages of green chop
- energy and labor intensive
- stage of maturity problems
- rain problems, hauling water accumulated on forage during wet weather
Hay has to be dried to ______ moisture for safe storage without mold
examples of perennials
orchardgrass kentucky bluegrass timothy smooth bromegrass tall fescue
examples of annuals
wheat
rye
oats
