Feeding BioFuels Co-products to
Livestock:
Challenges to Animal Health
NIAA, Sacramento, 4/2/07
Gavin L Meerdink, DVM, D.ABVT
Where to put the corn . . . . ?
User Definitions:
Based on consistency of product
• Coproduct
• the output of a consistent process
– materials from a “consistent,” quality conscious
manufacturing process which has “predictable” food value
– (distillers grains, corn gluten, soy hulls, etc.)
• Byproduct
• material with inconsistent ingredients or quality that
can not be used for original intended purpose
– inconsistent materials; may be unknown constituents
– (corn screenings, gin trash, rejected grains, off-spec food
ingredients, litter, rinse water, etc.)
ETHANOL
Confusion
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•
•
•
•
•
•
DG
distiller’s grains
DGS distiller’s grains with solubles
DDGS distiller’s dried grains with solubles
Corn gluten feed--wet
Corn gluten feed
Corn gluten meal
Brewers dried grains
Malt sprouts
Distillers dried grains
2 Ethanol plant process types
• Wet Milling
• Dry Grind
Ethanol plant process types
• Wet Milling
– 1st: fractionation
»
steep in weak sulfurous acid solution
– starch, germ, fiber, protein
• Starch:
• Fiber:
hi fructose corn syrup
ethanol → DDGS (minor source)
corn gluten feed (wet or dry)
• Protein:
corn gluten meal
Ethanol plant process types
• Wet Milling
• Dry Grind
• Entire corn kernel ground, initial process
• Fermentation → ethanol
→ DDGS
• Most of the ethanol from dry grind process plants
Issues for Health,
• Variability
corn coproducts
(plant to plant; load to load)
» Routine analyses ‘may be’ warranted
• wet wt. v. dry wt.
Issues for Health,
• Variability
corn coproducts
(plant to plant; load to load)
• Phosphorus
– Ca:P ratios in cattle diets can vary 1:1 to 7:1
– If < 1:1 problem
Composition % D.M.
(NRC 1982)
Corn
protein
10.9
Crude
fiber
2.9
P
0.3
S
0.12
DDGS
25
9.9
0.7
0.33
28-33
5.4-10.4
0.42-0.99
(var)
Corn Gluten
Feed
26
9.7
0.8
0.23
Corn Gluten
Meal
67
2.2
0.5
0.39
Ca - P concentrations & Ratio Perspectives
Ca (%)
P (%)
0.5
CGM
0.16
0.82
CGF
0.36
0.71
DDGS
0.15
0.29
corn
0.03
common
cattle
diets
0.35
0.7
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
Issues for Health,
• Variability
corn coproducts
(plant to plant; load to load)
• Phosphorus → urolithiasis
• urinary calculi, calculosis, “water belly”, kidney
stones
• Inversion of Ca:P ratio
• Mg also a factor
– Also “high” in DDGS and CGF
– Max tolerated, ruminant diets ~ 0.4%
Issues for Health,
corn coproducts
• Variability (plant to plant; load to load)
• Phosphorus → urolithiasis
• Sulphur → Polioencephalomalacia
– S concentrations > ~0.25 %
hazard
– (difficult interpretation: multiple S compounds besides
sulfates and sulfides . . . AA, organic S’s, 5 oxidation
states)
– Copper (low diet—relation)
– Gradual diet incorporation:
especially naïve animals
Composition % D.M.
(NRC 1982)
Corn
protein
10.9
Crude
fiber
2.9
P
0.3
S
0.12
DDGS
25
9.9
0.7
0.33
28-33
5.4-10.4
0.42-0.99
(var)
Corn Gluten
Feed
26
9.7
0.8
0.23
Corn Gluten
Meal
67
2.2
0.5
0.39
Issues for Health,
corn coproducts
• Variability (plant to plant; load to load)
• Phosphorus → urolithiasis
• Sulphur → sulfates
• Copper deficiency
– Given affinity of Cu and SO4’s, DDGS & CGF have
been implicated in decreased Cu absorption
Issues for Health, corn coproducts: Other
• Whatever else came with Corn + plant additions during
processing
– Mycotoxins
(do survive processing)
• Aflatoxins: year/region; milk residues
• Ochratoxin: potential, regional
• Fumonisins: hazard in equine diets
– Antimicrobial agents (processing aids)
• Virginiamycin, others (?)
– Residues (animal products, environment)
Future?
( . . for example)
• US Dept of Energy investment $385 mil in
six plants throughout US:
– “Cellulosic ethanol conversion technologies &
commercialization”
– Research on novel source materials:
• plant cellulose materials, e.g., stovers, straws,
grasses, cobs, etc.
• Vegetable wastes
• Wood chips
• Landfill green & wood waste
BIODIESEL
• Sources:
What are they?
– Soybeans
– other oil seed sources
– Lipids . . other sources
• What are the coproducts??
Biodiesel CoProducts issues:
• Glycerin (glycerol)
– Energy source
– Nutritional research needed
• Methanol . .
• Animals, particularly ruminants, less sensitive to
methanol than humans
• CO2 + H2O –> O=CH–OH (formate) –>
O=CH2 (formaldehyde) –> CH3–OH (methanol)
–> CH4 (methane)
Biodiesel CoProducts issues:
• Source dependent
• e.g., raw soybeans do contain antimetabolite
compounds
• Residues
– Particularly from non-ag crop residues??
Contamination: e.g., Dioxins
• Twenty dioxin (D)/furan (F)/polychlorinated
biphenyl (PCB) congeners were measured in
yellow grease (waste fats and oils from
restaurants) and in rendered fat from cattle,
poultry, swine and mixed animal species (8 -18
samples per commodity). The total D/F/PCB
levels found ranged from 0 to 1.6 parts per
trillion (ppt) toxic equivalents (TEQ). These
levels were below the 3.0 ppt TEQ maximum
residue limit (MRL) recently proposed by the
European Communities (EC) for D/F/PCB in
animal fat. (Dr. Lovell, FDA, 2005)
Grain CoProducts use future:
– CoProducts will change as processes change
for extraction of new product
• New product extraction techniques
– Economics
• Tax abatements
• Source commodities prices
• Processing costs/efficiencies
• More attention will be focused toward
coproducts when profit from them is
needed.
Presently:
“The SAFETY of grains coproducts at this
time ultimately rests upon the user.”
* * * *
Eventually:
Plants should become more involved with
product safety and problem investigation.
(for their own protection)
Acknowledgements
•
•
•
•
Ronald Belyea, U. of Mo
Kent Rausch, U of IL
Mike Tumbleson, U of IL
V. J. Singh, U of IL
Rausch, Belyea: The future of Coproducts from corn
processing. Appl Bioch Biotech 128(47-85), 2006.
Mineral Tolerances of Animals, 2nd Rev Edition. NRC of the
National Academies, 2005
Cost Comparisons
(Feedstuffs; 3/26/07; Chicago)
$/Ton
Protein %
Corn (@ $2.10/bu)
$147
10.9
Soybean Meal
$217
48
DDGS
$133
25
Corn Gluten Feed
$98
26
Corn Gluten Meal
$365
67