2010 Hay Production School
Hay Preservatives
Hay Heating and the Use
of Hay Preservatives
Dr. Dennis Hancock
Extension Forage Specialist
Crop and Soil Sciences – UGA
The other extreme…
Determining Moisture
Hay Moisture Probe
Methods:
3. Hay Moisture Testers/Probes
2. By feel (if calibrated).
1. Microwave moisture test
Contacts
Dr. Dennis Hancock
Extension Forage Agronomist
1
2010 Hay Production School
Hay Preservatives
Losses During Storage
HEAT
• Even when hay is baled at the target moisture
(15% moisture for round bales; 18% for squares),
the forage will go through a “sweat” for 2-3 wks.
Mold Spores
 Moisture is driven off, heat is given off, and DM dec.
 A 1% decrease in moisture ≈ 1% decrease in DM
 Moisture tends to equilibrate at 12% during storage
20% Moisture
H2O + CO2
A
Aspergillus
ill
Penicillium
12% Moisture
O2 + H2O
1000 lbs DM
Carbohydrates
(sugars)
920 lbs DM
Causal Agents of Hay Heating
70
110
150
190
230 270
CO
CO2 2
CO2
Hay Temperature | Risk Levels
310° F
70
Plant
Respiration
110
Normal Range
Safe
150
190
Heat
Damage
230 270
Fire Danger
Fungi and Bacteria
Heat-Resistant Fungi
Exothermic Chemical Reaction
(combustion)
Bale Moisture Effects Bale Temp
Temperaature, °F
150
33% Moisture
125
25% Moisture
100
75
HEAT
A
Aspergillus
ill
Penicillium
17% Moisture
O2 + H2O
0
10
20
Days
Dr. Dennis Hancock
Extension Forage Agronomist
30
40
Carbohydrates
(sugars)
Small Squares
Coblentz et al., 2000. Crop Sci.
2
CO
CO2
2
Bacterial
CO2
Decomposition
310° F
2010 Hay Production School
Hay Preservatives
Organic Acids are Corrosive
Hay Preservation Additives
• Rock Salt
No effect on mold growth
I
Increases
palatability
l
bili
Not recommended.
Same baler, 2 months later.
Hay Preservation Additives
Hay Preservation Additives
• Bacterial/microbial inoculants
• Anhydrous ammonia
Those tested have no consistently
demonstrable effect.
Prevents heating & inc. nonprotein N.
Some have had inconsistent
Safety and toxicity issues are a
concern, as well as cost.
effects (some positive, some no change).
Effectiveness in Humid South is
questionable (high humidity)
Only option when moisture is >
25%.
Requires real-time moisture
measurement (rate adjustment)
Hay Preservation Additives
• Organic acids
• Buffered acids
Prevents heating,
g but maintains moist
environment for microbial activity.
DM losses often offset DM gains.
Beneficial when moisture is 18 – 25%
Dr. Dennis Hancock
Extension Forage Agronomist
3
2010 Hay Production School
Hay Preservatives
Resources
www.georgiaforages.com
Dr. Dennis Hancock
Extension Forage Agronomist
4