2014 Southeast Hay Convention
Preventing Hay Molding and Heating
Preventing Hay Molding
and Heating
Dr. Dennis Hancock
Extension Forage Specialist
Crop and Soil Sciences – UGA
The other extreme…
Temperature, °F Bale Moisture Effects Bale Temp
150 33% Moisture
125 25% Moisture
100 75 17% Moisture
0
10
20
Days Picture Credit: G.J. Charlet III, Clinton, LA Vol. Fire Dept. via flickr.com
Maximum Internal Bale Temperature (Coblentz and Hoffman, 2009)
30 40 Small Squares
Coblentz et al., 2000. Crop Sci.
Losses During Storage
•  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.
§  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
12% Moisture Safe Temperatures
1000 lbs DM Coblentz and Hoffman
(2009)
Dr. Dennis Hancock
Extension Forage Agronomist
1
920 lbs DM 2014 Southeast Hay Convention
Preventing Hay Molding and Heating
HEAT
Causal Agents of Hay Heating
Mold Spores
70
110 150
190
230 270
310° F Plant
Respiration
Aspergillus Penicillium Fungi and Bacteria
Heat-Resistant Fungi
O2 + H2O
CO2
CO2
CO2
Carbohydrates
(sugars)
Exothermic Chemical Reaction
(combustion)
Hay Temperature | Risk Levels
70
110 150
Normal Range
Safe
Heat
Damage
190
230 270
310° F Fire Danger
Hay Moisture Probe
Accuracy of Various Hay Moisture
Probes – 4th cutting Bermudagrass
40
Actual
FtP
JD
Hay Moisture (%)
35
Contacts
30
DW
FtW
PA
25
20
15
10
5
0
10 a.m.
Dr. Dennis Hancock
Extension Forage Agronomist
2
1 p.m.
3 p.m.
2014 Southeast Hay Convention
Preventing Hay Molding and Heating
Determining Moisture
Determining Moisture
Methods:
4. Hay Moisture Testers/Probes
3. By feel (if calibrated).
2. Microwave moisture test
Methods:
4. Hay Moisture Testers/Probes
3. By feel (if calibrated).
2. Microwave moisture test
1. Moisture tester (e.g., Koster)
Hay Preservation Additives
HEAT
•  Rock Salt
No effect on mold growth
Aspergillus Penicillium O2 + H2O
Carbohydrates
(sugars)
CO
Increases palatability
Not recommended.
CO2
2
Bacterial
CO2
Decomposition
Hay Preservation Additives
Preservatives
Application of Propionic Acid Preservative1 to Large Square Bales2
of Alfalfa/Orchardgrass Hay (Coblentz and Coffey, unpublished)
•  Organic acids
•  Buffered acids
Group
Prevents heating, but maintains moist
environment for microbial activity.
DM losses often offset DM gains.
3
Wet
Weight
Dry
Weight
DM
Density
%
ft3
lbs
lbs
lbs DM/ft3
High
27.4
40.7
644
467
11.5
Medium
23.8
40.7
626
476
11.8
Low
19.6
42.1
613
494
11.7
SEM
0.80
0.39
9.3
10.4
0.20
Beneficial when moisture is 18 – 25%
Dr. Dennis Hancock
Extension Forage Agronomist
Moisture Volume
1
Rates: 0, 0.6, or 1.0% of fresh weight.
2
Large square bales were 3 x 3 x 6 ft.
2014 Southeast Hay Convention
Preventing Hay Molding and Heating
Maximum Temperature
65
130
1.0%
0.6%
1.0%
0%
120
110
100
0%
61
59
57
90
80
0.6%
63
NDF, %
Maximum Temperature, oF
NDF
High (27.4%)
(Coblentz and Coffey, unpublished)
Medium (23.8%)
55
Low (19.6%)
High (27.4%)
Medium (23.8%)
Low (19.6%)
Moisture, %
Moisture, %
(Coblentz and Coffey, unpublished)
Organic Acids are Corrosive
Organic Acids are Corrosive
Same baler, 2 months later. Hay Preservation Additives
•  Bacterial/microbial inoculants
Those tested have no consistently
demonstrable effect.
Some have had inconsistent
effects (some positive, some no change).
Effectiveness in Humid South is
questionable (high humidity)
Requires real-time moisture
measurement (rate adjustment)
Dr. Dennis Hancock
Extension Forage Agronomist
Photo credit: Dr. Garry Lacefield, Univ. of Kentucky
4
2014 Southeast Hay Convention
Preventing Hay Molding and Heating
Silage & Haylage
Baled Silage
SILAGE - Forage that has
undergone anaerobic
fermentation
Less dependent on
weather
Makes use of some
forages that other-wise
wouldn’t work.
Quality Advantages
•  Enables
•  Lowered
•  Less
§
§
§
www.georgiaforages.com
1-800-ASK-UGA1
risk of rain damage
shatter loss
•  Higher
§
Questions?
timely harvest
forage quality1
Lower NDF, ADF, ADL
Higher CP
Increased digestibility
Increased palatability
•  However,
Dr. Dennis Hancock
“Garbage in = Garbage out!”
1
Extension Forage Specialist
Crop and Soil Sciences – UGA
Han, et al. 2005; Hancock and Collins, 2006.
Dr. Dennis Hancock
Extension Forage Agronomist
5