Progress on Pit Foaming (what we know, what we dont know, what were - PowerPoint PPT Presentation

Progress on Pit Foaming (what we know, what we don’t know, what we’re doing) 2015 Iowa Pork Congress Dan Andersen, PhD Steve Hoff, PhD Dept. of Ag & Biosystems Engineering Iowa State University Brian Kerr, PhD Steve Trabue, PhD USDA-ARS National Center for Agriculture and the Environment Ames, Iowa January 28, 2015

Objectives for Today Update on IPPA-funded Pit Foaming Research Summarize Results Precautionary Measures

Overall Foaming Requirements Three-phase Process: 1. Gas generation (i.e. methane, hydrogen sulfide) , 2. Surface tension reduction (surfactants; bio- or otherwise) , 3. Bubble support structure (i.e. small fibers) . A surfactant causes surface to “elasticize” Foam supported by bacteria H 2 S CH 4 or fine fibers or ?? H 2 S CH 4 H 2 S CH 4 Gases otherwise naturally escaping at very low concentrations are trapped

In-field Foaming Foam Creeping Through Slats (4 ft of foam case) Photo courtesy of Dr. Larry Jacobson, UMN Foam Into Animal Occupied Zone Photo courtesy of Dave Preisler, MPB; Dr. Larry Jacobson, UMN

Curious Nature of Foaming  Has occurred in one pit of side-by-side rooms with equalizing channel.  Commonly found in one barn of multi-barn sites with common genetics, feed, management, etc.  Attempts at correlating foaming vs non-foaming barns with multiple factors has been elusive. Photo courtesy of Dr. Larry Jacobson, UMN

IPPA Funded Research Project GOAL: Finding and Correcting the Mechanisms of Foaming Photo courtesy of Dr. Larry Jacobson, UMN

IPPA Funded Research Effort  Multi-state effort (ISU, UMN, UILL) involving 20+ academic professionals with expertise in manure management, chemistry, microbiology, feed rations, and digestibility  $1M investment over three years (we are finishing YR2)  Project managed by Iowa State University  Our team is working diligently to solve this problem

Multi-state Research Collaboration ISU/USDA-ARS UMN • Feed trials Chuck Clanton • Extensive producer Chemical composition • Dan Andersen Larry Jacobson survey analysis Brian Kerr • Microbial analysis • Methane production Bo Hu Foaming potential • Foaming potential • Steve Trabue Brian Hetchler testing testing UILL Organize all manure • sampling and distribution Microbial analysis • Rich Gates, Angela Kent, Laura Pepple

Theory • Biogas Generation of methane, CO 2 and hydrogen sulfide. • Surfactants Materials that significantly change the surface tension. • Stabilizer Increases the stability of foam bubbles, like small fibers and other hydrophobic particles.

Hypotheses - Mechanism (1) Increased prevalence of foaming is due to increased biogas/methane production from the manure (2) Elevated concentrations of surface active agents in foaming manures are causing greater gas capture (3) Foam is being stabilized by small particles/proteins (4) Differing physical, chemical, and biological properties are related to dietary inputs.

Hypotheses - Microbial • Brief Background • ARISA & Sequencing • Site, Management, and Environmental Factor Database • Objective 1 – Microbial community differences • Objective 2 – Identify relevant microbes using sequencing • Objective 3 – Use relational database with Obj’s 1 and 2 • Methanogen Sequencing

Manure Sampling SOP Samples were collected from discrete depths A foam/crust in the manure storage pit. B transition Samples from 2 Integrators Over 60 Sites Generated more than 2000 manure samples C slurry D sludge

Sample Summary: Cases I NTEGRATOR� A� � I NTEGRATOR� C LASSIFICATION � B� # � S AMPLES � � # � S AMPLES � OF� OF� � � N ON -F OAMING � 250� � 183� F OAMING � 255� � 362� N OT� T REATED � 178� � 163� T REATED � 327� � 362� P REVIOUS� P UMP� O UT � 24� � 18� F ALL� 2012� 337� � 460� S PRING� 2013� 142� � 38� F ALL� 2013� 2� � 9� C ASE� 1 � ( FOAMING )� 115� � 76� C ASE� 2 � ( NON - FOAMING )� 85� � 258� C ASE� 3 � ( TRANSITION )� 157� � 111� C ASE� 4 � (U NSTABLE )� 148� � 80� T OTAL � 505� � 525�

Why Foam? Why Now? Diet composition and particle size effects on nutrient excretion Digestion/Excretion Output Estimated C Diet ID Diet Composition Coefficient Output, kg 1 difference, kg Equivalence, kg 2 4.6% EE 63% (37%) 6,592 C-SBM 7.0% NDF 66% (34%) 9,223 17% CP 88% (12%) 7,905 45% Carbon 91% (9%) 15,694 C-SBM + FIBER 6.2% EE 63% (37%) 8,889 2,297 (+35%) 28% 13.8% NDF 68% (32%) 17,112 7,889 (+85%) 55% 17% CP 85% (15%) 9,881 1,976 (+25%) 17% 46% Carbon 87% (13%) 23,291 7,597 (+48%) 1 Output based upon 310 kg feed/pig from wean-to-finish and 1,250 pigs/barn. 2 Lipid = 76% carbon; Protein = 53% carbon; Fiber = 45% carbon.

Dietary Tidbits • Averaged across 3 trials in our metabolism/tank studies, high fiber diets increased manure carbon by approximately 40%. • Intact fats are less digestible than ‘added’ fats (e.g., 65% versus 85%, respectively). • We do not know any interactive effects between fiber and lipid type, or between fiber and lipid level. • On average, grinding to a finer particle size, 374 vs 631  m, improved FAT , FIBER, CP , and C digestibility by 30, 8, 3, and 3%, respectively. In general, finer grinding improves digestibility of low-digestible ingredients more than high-digestible ingredients. • DDGS of 340 μ m exhibited an FAT digestibility of 75% compared to 57% for DDGS of 650 μ m

Diets in Practice: More C in manure, more methane potential

How do you study the gas phase? (Methane % 1 100)(Biogas Produced mL + V headspace ) × ρ manure ( g mL) L × 1440 minutes MPR = L ∗ day Mass of sample g × incubation period(minutes) day

Methane Production Rates • Methane production rate was higher in foaming barn than non-foaming barns. • Why?

What would cause this difference? • Quantity of carbon inputs? • TS, VS, VFA • Source of carbon? • BMP , VFA • Differences in microbes? • Degraders, methanogens, sulfate reducers • Microbial community structure • Response to different carbon substrates? • Differences in pathways/response to substrate ?

Quantity of Food? 9 A A A Foaming Non-Foaming 8 B Volatile Solids (%) 7 B 6 C D 5 4 3 2 1 0 A B C D Sample Depth 12 Foaming Non-Foaming A A A 10 B C Total Solids (%) 8 D E 6 4 2 0 A B C D Sample Depth

Quality of Food? • Difference between foaming and non-foaming, but non- foaming is better and driven by VFA’s • More solids deeper in the manure, but quality of those solids is lower

Microbial Data – What your looking at

Microbial Differences? • Foaming and non-foaming sites have distinct microbial communities • Sequencing Data

Microbial Richness (Diversity) Integrator A Integrator B

So which microbes are these? 20% non.foaming 18% foaming 16% 14% 12% 10% 8% 6% 4% 2% 0% • Differences in relative abundance of dominant taxa are associated with foaming — but no new microbes.

So can these microbes be related to management practices?

So what is influencing these microbes? Integrator B

Is this related to functionality? Integrator B

So do they like a certain food better?

What about surfactants? Difference between F and NF – driven by VFA concentrations Difference between B and C&D driven by ??? (oil/long chain fatty acids) What is role of particles/proteins?

Surfactant should drive capacity to foam Generally small differences in ability of manure to foam.

What stabilizes foam? 9 A A A Foaming Non-Foaming 8 B Volatile Solids (%) 7 B 6 C D 5 4 3 2 1 0 A B C D Sample Depth • What did we notice about samples that stabilized • Solids rich, but finer looking solids, not big chunks • Liquid drained more slowly from the foam • Sort of set up, with solids in bubble matrix • Good foams grey/brown (protein), bad foams were white/clear (fats/oils)

Foam is really stable 1800 1600 Foaming Foam Half-Life (Minutes) 1400 Non-Foaming 1200 1000 800 600 400 200 A B B B B B 0 A B C D Sample Depth

The foam stays wet - viscous 12 As Is A 10 Centrifuged Viscosity (cP) Filtered 8 6 B B 4 a 1 2 b b 2 2 0 Foam Foaming Manure Non-Foaming Manure Its not just the solids, something else is giving us viscosity in the foam. -sugar, oil, lipopolysaccharides, proteins? Microbial goo

but… Particles hold it together 1 Fraction of Particles Finner Foam 0.9 Foaming Manure 0.8 Non-foaming Manure 0.7 0.6 0.5 0.4 0.3 0.2 0.1 0 0.01 0.1 1 10 100 1000 Particle Size (um) 200 Averag Particle Size (um) 180 160 140 120 100 80 60 40 20 0 Foam Foaming Manure Non-foaming Manure

Does diet influence these particles? 0.20 Fraction of Particles in C-SBM-C C-DDGS-C C-SH-C C-SBM-F 0.16 C-DDGS-F C-SH-F Size Class 0.12 0.08 0.04 0.00 0.0 0.3 2.0 16.0 128.0 1,024.0 Particle Size ( μ m) Greater percent of particles were fine silt particles from inoculated manure (p < 0.05) & courser grind (p = 0.1254)