Fescue Toxicosis in Beef Cattle: Understanding and Managing the Problem - Joe Sellers, Iowa State University Extension; Dr. Scott Flynn, Dow AgroSciences, from the 2014 Iowa Cattle Industry Convention, December 8 - 10, 2014, Des Moines IA, USA
More presentations at http://www.trufflemedia.com/agmedia/conference/2014-iowa-cattle-industry-convention
2. How is fescue a problem in
Iowa?
• It is moving further north
• It is colder here than in other fescue belt
states
• We have lost a lot of improved non-fescue
pastures (35% less pasture than 2002)
• Increasing spring growth with N makes it
worse
3. Questions I get
• Does clipping stop the problem?
• How long does it effect the cattle after they are
removed from fescue?
• Are some cattle immune to the effects?
• Do some mineral additives eliminate the
problem?
• How do I identify it?
4. Tall Fescue Endophyte Life Cycle
Active
endophyte
fungus
infects new
grass seedling
Fungus enters
the rapidly
elongating
stem tissue
Fungus Mycelium
invades the
developing seed
Grass Vegetative Stage:
Most Active Fungus Growth
in Leaf Sheaths
5. Fescue BMPs
• Keep vegetative
• Introduce legumes
• Careful with N fertilization
• Fescue toxicosis is a health disorder, not
nutritional, but --
• You must meet cow mineral requirements
• Dilute with other feeds, forages
• Renovate with spray/smother/spray
6. Fescue BMPs
• Good for calving pastures
• Hay will have 50% alkaloid level compared
to grazed
• If stockpile, do it from August 1
• Source genetics from herds with fescue
• Mineral additives – some data finds
response, but mixed results
7. Vasoconstriction (narrowing of blood vessels)
Fescue foot
Poor thermoregulation
Low feed intake
Low rate of gain
Dystocia (birthing problems) and poor reproduction
Aglactia (poor milk production)
Fescue Toxicosis
11. Problems exist even if native
cattle and no visible signs
• Gain and reproductive losses
• Seed heads and stems are worse, but
alkaloids are in all of the plant
• Year to year and seasonal differences
12. 1999 2000
------- lb/d -------
Toxic endopyte 0.73 0.50
Endophyte-free 1.26 1.56
Novel endophyte 1.30 1.54
Steer gains on three
types of fescue
15. Alkaloid Management!
In endophyte (replant)
In plant (fertilizers, seasonal, anatomical)
In pasture (dilution, rotations)
In diet (ammoniation, supplementation)
16. Spray Smother Spray Renovation
Experiment with small acreage
Plan for fall plant if possible (Sept. 1 for mid-MO)
If replacing E+ KY31, may clip seed heads in spring
Also if replacing E+ KY31, “spray-smother-spray”
Add legumes later (except for BFT)
15 lb/A drilled; 1/8” deep
Add N for “pop-up” (30 to 40 lb/A)
Old
Stand
Summer
Annual
New
Stand
spray & plant
Spring Summer Fall
spray & plant
Yield
23. Grazing stockpile
• Reduces Hay 2390/lbs per cow compared
to dry lot (three year average)
• Stockpile from around August 1 for beef
balance of yield and quality
• Graze cornstalks first, then stockpiled
fescue (quality, less alkaloids in fescue)
25. Pasture management
is important
• www.iowabeefcenter.org
• Joe Sellers, 641-203-1270
• sellers@iastate.edu
• Welcome, Scott Flynn, Dow AgroSciences