Mitigation of Ammonia Emissions from Broiler Houses Using a Biodegradable Litter Amendment ...

167 Pages·2013·1.75 MB·English

Mitigation of Ammonia Emissions from Broiler Houses Using a Biodegradable Litter
Amendment

Namanda Sara Senyondo

Dissertation submitted to the faculty of the Virginia Polytechnic Institute and State
University in partial fulfillment of the requirements for the degree of

Doctor of Philosophy
In
Biological Systems Engineering

Jactone A. Ogejo - Chair
Robert Grisso
Rory O. Maguire
Frank W. Pierson
Mary Leigh Wolfe

April 03, 2013
Blacksburg, VA

Keywords: Ammonia Emissions, Broiler Litter, Biodegradable, Litter Amendment,
Mitigation.
Mitigation of Ammonia Emissions from Broiler Houses Using a Biodegradable Litter
Amendment
Namanda Sara Senyondo
ABSTRACT
Broilers are raised indoors on high density farms with bedding/litter to trap their manure.
Ammonia gas, which is produced as the manure decomposes, has adverse effects on human
health, bird welfare and the environment. Using litter amendments can reduce the amount and,
consequently, the effects of ammonia emitted from broiler houses. The objective of this study
was to determine the effectiveness of a biodegradable litter amendment (BLA) in reducing
ammonia emitted from a broiler house.
A pilot scale test was set up with six adjacent, individually ventilated rooms and a stocking
density of 0.07 m2 per bird. The birds were fed with a standard commercial, corn and soybean
meal based diet and water was provided ad libitum. The first flock was grown on 10 cm of fresh,
kiln-dried pine shavings, while subsequent flocks were grown on top-dressed reused litter. The
two treatments (control (CTL) and BLA) were randomly assigned to the six rooms after flock 1,
to give three replicates per treatment. The exhaust air from the rooms was sampled for ammonia
concentration for two days each week starting at four days of age to determine the amount of
ammonia emitted.
Over three subsequent flocks, the total mass of ammonia emitted from rooms treated with BLA
was 31% to 47% lower than the control. Ammonia emitted per bird grown on treated litter and
per kg of harvested bird weight was 32% to 44% lower, and the exhaust fans ran 7% to 22% less
than CTL over the same period. For both BLA and CTL, the amount of ammonia emitted
generally increased with bird age and litter reuse. The study showed that BLA effectively
reduced ammonia emitted from a broiler house and that there are potential energy savings from
using the amendment. However, ammonia emitted from the BLA rooms during the final flock
was 57% higher than CTL, which was attributed to insufficient water (less than 18% moisture by
weight) to support the reaction between BLA and ammonia.

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Acknowledgement
My sincere appreciation goes to my advisor, Dr. Jactone A. Ogejo for giving me the
opportunity to conduct this research and for his continued guidance throughout my graduate
studies and compilation of this dissertation.
I would also like to thank my committee members; Dr. Robert Grisso, Dr. Rory O.
Maguire, Dr. F. William Pierson and Dr. Mary Leigh Wolfe, who provided valuable advice,
shared scholarly resources, and availed members of their research teams to help with my field
study.
I would not have been able to complete the field study without help from fellow students;
Andrea, Ashley, Caitlin, Devin, Hassan, Jess, and Liz, and staff at the VT turkey farm, Curt and
Dale. We somehow managed to have fun weighing chicken for hours at a time. Thank you.
This journey has been a challenge on many levels but I have seen the goodness of God in
family, friends and strangers alike; in people like Eunice Ofori that prayed for and with me, and
watched my son so I could work late or simply get some rest. I received an enormous amount of
encouragement and support from my parents, siblings and longtime friends, Gloria and Brenda.
Thank you.
Finally, to my dear son Bradley; there is so much that I wish for you but hopefully I will
inspire you to believe in yourself, work hard and achieve your own dreams. God bless you.
This work was supported by the National Institute of Food and Agriculture (NIFA),
U.S. Department of Agriculture, under Agreement No. 2009-55112-05214.
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Table of contents
Abstract ........................................................................................................................................... ii
Acknowledgement ......................................................................................................................... iv
Table of contents ............................................................................................................................. v
List of figures ............................................................................................................................... viii
List of tables .................................................................................................................................... x
List of abbreviations ...................................................................................................................... xi
List of elements and chemical formulas ...................................................................................... xiii
CHAPTER 1: INTRODUCTION ................................................................................................... 1
Poultry production in the U.S. ........................................................................................................ 1
Objectives of the study.................................................................................................................... 3
CHAPTER 2: LITERATURE REVIEW ........................................................................................ 5
The nitrogen cycle and sources of ammonia in the environment ................................................... 5
Structure and management of commercial broiler houses .............................................................. 7
Formation of ammonia in broiler houses ...................................................................................... 10
Chemistry of ammonia .................................................................................................................. 12
Factors affecting ammonia volatilization...................................................................................... 15
Effects of ammonia on broiler health............................................................................................ 22
Effects of ammonia on the environment ....................................................................................... 24
Effects of ammonia on human health ........................................................................................... 25
Quantification of ammonia emissions .......................................................................................... 27
Modeling ammonia emissions ...................................................................................................... 30
Mitigation of ammonia volatilization from broiler litter .............................................................. 32
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Evaluation of flock performance .................................................................................................. 38
Summary ....................................................................................................................................... 41
References ..................................................................................................................................... 43
CHAPTER 3: MITIGATING AMMONIA EMISSION FROM BROILER HOUSES USING A
NOVEL BIODEGRADABLE LITTER AMENDMENT ............................................................ 59
Abstract ......................................................................................................................................... 59
Introduction ................................................................................................................................... 61
Materials and methods .................................................................................................................. 64
Results and discussion .................................................................................................................. 74
Conclusion .................................................................................................................................... 90
References ..................................................................................................................................... 91
CHAPTER 4: THE EFFECT OF USING A BIODEGRADABLE LITTER AMENDMENT TO
CONTROL AMMONIA EMISSIONS ON BIRD WEIGHT, FEED EFFICIENCY, FOOTPAD
DERMATITIS AND LITTER CHARACTERISTICS ................................................................ 96
Abstract ......................................................................................................................................... 96
Introduction ................................................................................................................................... 98
Materials and methods ................................................................................................................ 100
Results and discussion ................................................................................................................ 103
Conclusion .................................................................................................................................. 113
References ................................................................................................................................... 114
CHAPTER 5: EMPIRICAL MODELS FOR ESTIMATING AMMONIA EMISSIONS FROM
BROILER HOUSES ................................................................................................................... 118
Abstract ....................................................................................................................................... 118
Introduction ................................................................................................................................. 120
Materials and methods ................................................................................................................ 123
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Results and discussion ................................................................................................................ 128
Conclusion .................................................................................................................................. 139
References ................................................................................................................................... 140
CHAPTER 6: GENERAL CONCLUSION AND RECOMMENDATIONS ............................ 143
APPENDICES ............................................................................................................................ 146

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List of figures
Figure 2-1: The nitrogen cycle ........................................................................................................ 5
Figure 2-2: Mineralization of uric acid to ammonia ..................................................................... 11
Figure 2-3: Fraction of ammonia species as a function of temperature and pH ........................... 17
Figure 3-1: Broiler house layout ................................................................................................... 64
Figure 3-2: Fan performance curve showing the relationship between air flow and static pressure
drop across the fan ........................................................................................................................ 66
Figure 3-3: Setup of equipment within rooms .............................................................................. 67
Figure 3-4: Layout of sensors in a portable monitoring unit ....................................................... 69
Figure 3-5: Diurnal changes in room temperature and litter temperature during flock 2 ............ 80
Figure 3-6: Ventilation rate, room NH concentration, emission rate and NH emitted during
3 3
flock 3 (Aug. to Sep. 2011) ........................................................................................................... 83
Figure 3-7: Ventilation rate (VR), NH concentration, emission rate (ER) and NH emitted
3 3
during flocks 2 through 5 (Jun. 2011 to Jan. 2011) ...................................................................... 85
Figure 4-1: Guide for scoring footpad dermatitis ....................................................................... 102
Figure 4-2: Effect of location on litter moisture, TAN, pH and TN during flock 2 ................... 109
Figure 5-1: Experimental setup for determining ammonia flux from broiler litter .................... 124
Figure 5-2: Ammonia flux from BLA and CTL at constant air temperature .............................. 130
Figure 5-3: Ammonia flux from BLA and CTL at constant air flow ......................................... 131
Figure 5-4: Predicted vs. actual flux from CTL and BLA – lab data ......................................... 133
Figure 5-5: Relative sensitivity of CTL and BLA flux model output at constant temperature .. 135
Figure 5-6: Relative sensitivity of CTL and BLA flux model output at constant VR ................ 136
Figure 5-7: Estimated and observed ammonia flux from flocks 2 and 3 from CTL and BLA ... 138
Appendix A: BLA flux model parameter estimates ................................................................... 147
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Appendix B: BLA flux model leverage plots ............................................................................. 148
Appendix C: CTL flux model parameter estimates .................................................................... 149
Appendix D: CTL flux model leverage plots ............................................................................. 150
Appendix E: Litter characteristics after flock 3 .......................................................................... 151
Appendix F: Litter characteristics after flock 4 .......................................................................... 152
Appendix G: Litter characteristics after flock 5 ......................................................................... 153

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List of tables
Table 3-1: Exhaust fan run time in hours during flocks 2 through 5 ............................................ 74
Table 3-2: Weekly mass of ammonia emitted for flocks 2 through 5 .......................................... 76
Table 3-3: Environmental conditions and litter characteristics during the study ......................... 78
Table 3-4: Mean daily ammonia emission rate from this study vs. published data ...................... 81
Table 3-5: Ammonia emission rate per kg of live flock weightat different growth stages during
flocks 2 through 5 ......................................................................................................................... 86
Table 3-6: Comparison of daily NH emission rates: this study vs. published data ..................... 87
3
Table 3-7: Comparison of reduction of ammonia emitted: BLA vs. common litter amendments 89
Table 4-1: Bird performance (FPD, FCR and mean weight) during flocks 2, 3, 4 and 5 ........... 104
Table 4-2: Correlation between prevalence of footpad dermatitis and litter characteristics ...... 106
Table 4-3: Litter TAN, TN, moisture content and pH during 4 flocks grown on reused litter ... 107
Table 4-4: Comparison of litter mineral concentration from this study to published data ......... 111
Table 5-1: Litter characteristicsbefore and after emissions tests ................................................ 128
Table 5-2: Mean ammonia flux at 0.10, 0.58 and 1.02 Lpm ...................................................... 129
Table 5-3: Mean ammonia flux at 10, 23 and 31 oC ................................................................... 129
Table 5-4: Empirical models for estimating ammonia fluxes from broiler litter using temperature
and ventilation rate ...................................................................................................................... 133

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