1 Attachment 

Sona,

As explained below, the District’s current VOC emission factors for cattle other than mature milk cows are 

conservative estimates based on the VOC emissions measured for mature milk cows. This is currently the best 

information available on emissions for cattle at this time because several iterations of research efforts and 

projects have been completed, reviewed, and refined to determine emissions from mature milk cows and their 

feed. Such an extensive effort has not yet been undertaken to measure VOC emissions from support stock 

because there are fewer of them and they have much lower VOC emissions. As explained below, we currently 

adjust the dairy emission factor for support stock based on volatile solids excretion, which gives an approximate 

amount of organic matter contained in manure. This gives a conservatively high estimate of VOC emissions from 

other cattle because heifers at a dairy will be fed a ration that has a higher percentage of relatively inert organic 

matter, such as lignin and cellulose, while dairy cows will be fed a much higher amount of fermentable 

carbohydrates and silage. Although fermentable carbohydrates and the alcohols and volatile fatty acids from 

silage will lead to much higher VOC emissions when consumed or excreted in manure, measurements of volatile 

solids does not distinguish between the different forms of organic matter and may not even capture the higher 

amounts of alcohols in dairy manure compared to other cattle as these would tend to volatilize before 

completion of the measurement.

The composition of the diet fed to cattle is now known to be an important factor that affects emissions. In 

RE: uncertainty associated w/ emission factors for other cattle 

Ramon Norman 

to: 

Sona Chilingaryan 

08/19/2011 04:58 PM 

Cc: 

Andrew Steckel, Kara Christenson, "Samir Sheikh", "Sheraz Gill" 

Hide Details 

From: "Ramon Norman" <Ramon.Norman@valleyair.org>

To: Sona Chilingaryan/R9/USEPA/US@EPA 

Cc: Andrew Steckel/R9/USEPA/US@EPA, Kara Christenson/R9/USEPA/US@EPA, 

"Samir Sheikh" <Samir.Sheikh@valleyair.org>, "Sheraz Gill" <Sheraz.Gill@valleyair.org>

image001.gif

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general milk cows, which are fed diets that have higher amounts of fermentable carbohydrates, and volatile 

fatty acids from silage, are expected to have higher emissions for the amount of feed consumed or manure 

produced in comparison to other cattle. Dr. Mitoehner’s recent beef cattle study confirmed the importance of 

diet on the potential for emissions. The majority of cattle included in his study were actually Holsteins – the 

most common breed used for dairy cattle in California. When these Holstein steers were fed feedlot cattle diets, 

the emissions of alcohols were much lower than what had been measured for Holstein milk cows. It is expected 

that similar results of lower emissions would be seen with heifers, which like feedlot cattle, are fed a diet 

designed to make them gain weight and reach maturity rather than produce milk.

Please let me know if you have any questions or if we can provide anything else. 

From: Chilingaryan.Sona@epamail.epa.gov [mailto:Chilingaryan.Sona@epamail.epa.gov] 

Sent: Wednesday, August 17, 2011 2:42 PM 

To: Ramon Norman 

Cc: Steckel.Andrew@epamail.epa.gov; Sheraz Gill; Christenson.Kara@epamail.epa.gov

Subject: uncertainty associated w/ emission factors for other cattle 

 

Hi Ramon, 

Based on some of the information below, it seems like there may be more uncertainty associated with emission 

factors for other cattle than dairies or beef feedlots. Is this the case? I'm not sure I fully understand everything that 

is at stake here-- can you please further explain why the emission factors for other cattle may have more 

uncertainty associated with them? 

Thanks much, 

s. 

----- Forwarded by Sona Chilingaryan/R9/USEPA/US on 08/17/2011 02:36 PM ----- 

From: "Ramon Norman" <Ramon.Norman@valleyair.org> 

To: Sona Chilingaryan/R9/USEPA/US@EPA 

Cc: "Samir Sheikh" <Samir.Sheikh@valleyair.org>, "Errol Villegas" <errol.villegas@valleyair.org>, "Sheraz Gill" <Sheraz.Gill@valleyair.org>, 

"Sandra Lowe-Leseth" <Sandra.LoweLeseth@valleyair.org> 

Date: 08/04/2011 05:19 PM 

Subject: FW: Draft Revision to Portioning of Dairy Cow Enteric and Manure Emissions Factors for Support Stock 

Sona, 

 

As we discussed a few days ago, I am sending draft calculations showing proportioning of the milk cow emission factor for 

support stock. VOC emissions are proportioned based on Volatile Solids excretion. As noted below, the District previously 

proportioned emissions using an equation from ASAE/ASABE D384.2 that used weight to estimate manure excretion but 

this equation overestimated manure excretion from smaller heifers and calves. 

 

Please note that in other discussions and correspondence with Dr. Meyer, she stated that the chemical composition of feed 

and volatile solids should be considered when proportioning VOC emissions. Volatile Solids are a good measure of organic 

matter that can be a substrate of VOC, but not all organic matter is equal. Milk cows are fed a ration that is much more 

digestible than support stock and the organic in their manure will produce more methane, CO2, and likely more VOC 

emissions than heifers that are fed a ration that is not as digestible and much less silage. Since we do not have information 

on the speciation of the volatile compounds in manure (maybe a future research project), I was going to look into using the 

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methane production potential as a volatile solids of milk cows vs. heifers to further refine the VOC emissions estimate for 

heifers but have had higher priorities to take care of. So this draft proportioning of emissions is considered conservative as 

it may still overestimate VOC emissions from heifers. 

 

From: Ramon Norman 

Sent: Monday, December 13, 2010 5:21 PM

To: Sheraz Gill; Martin Keast

Cc: Jim Swaney

Subject: Draft Revision to Portioning of Dairy Cow Enteric and Manure Emissions Factors for Support Stock 

 

I have attached my revised calculations for portioning the dairy enteric and manure emissions factors to the 

support stock. The VOC emissions are assumed to be proportional to Volatile Solids (VS) excretion and the 

Ammonia emissions are assumed to be proportional to Nitrogen (N) excretion. The values for VS and N excretion 

are taken directly from ASAE/ASABE D384.2 (March 2005) when available and estimated from averages of other 

resources when a value is not given (i.e. medium heifers and baby calves). I checked the estimated excretion 

values with Deanne Meyer to and she agreed that the formulas given in ASAE D384.2 are not appropriate for use 

with smaller animals since the formulas (especially the formula based on weight alone) will significantly 

overestimate manure production from smaller animals (see attached email). She also stated that the ASAE 

D384.2 equations had not been fully reviewed at the time of publication and updated equations can be found in 

the paper by Nennich (and others) "Prediction of Manure and Nutrient Excretion from Dairy Cattle". In one of the 

worksheets a comparison of the predictive formulas from ASAE D384.2 and Nennich is compared. 

 

Based on my calculations the percentage of emissions calculated for support stock will decrease in comparison to 

the original apportionment that was used - this is especially true of the baby calves and small heifers. I will run 

the revised excretion estimates by Deanne Meyer one more time to see if she has any suggestions. 

 

Finally, I suggest apportioning emissions based on solids/volatile solids rather than manure since the assumed 

moisture content has a large effect on total manure output. 

 

Ramon Norman 

Air Quality Engineer 

San Joaquin Valley Air Pollution Control District 

1990 E. Gettysburg Ave 

Fresno, CA 93726-0244 

Phone: (559) 230-5909 

FAX: (559) 230-6061 

[attachment "Dairy Animal Nutrient Excretion Estimates (12-13-10).xls" deleted by Sona 

Chilingaryan/R9/USEPA/US] 

----- Message from "Deanne Meyer" <dmeyer@ucdavis.edu> on Mon, 8 Mar 2010 15:47:53 -0700 ----- 

Ramon 

Attached is a word document with your questions and my responses related to manure excretion. I’m also attaching a 

manuscript that I refer to in the document. 

To: "Ramon Norman" <Ramon.Norman@valleyair.org> 

cc: <paulwud@callatg.com> 

Subject: manure numbers 

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Deanne

From: Ramon Norman [mailto:Ramon.Norman@valleyair.org] 

Sent: Monday, March 08, 2010 11:37 AM

To: Deanne Meyer

Subject: RE: more files 

 

Thanks 

 

Ramon Norman 

Air Quality Engineer 

San Joaquin Valley Air Pollution Control District 

1990 E. Gettysburg Ave 

Fresno, CA 93726-0244 

Phone: (559) 230-5909 

FAX: (559) 230-6061 

 

 

 

From: Deanne Meyer [mailto:dmeyer@ucdavis.edu] 

Sent: Monday, March 08, 2010 11:37 AM

To: Ramon Norman

Subject: more files 

 

 

From: Ramon Norman [mailto:Ramon.Norman@valleyair.org] 

Sent: Friday, March 05, 2010 4:49 PM

To: Deanne Meyer

Subject: RE: ::::RE: Silage Inoculants and Parameters or Practices to Reduce Emissions from Silage 

 

Hi Deanne, 

 

I was in a meeting and missed your call. We can try to talk on Monday. What time will work well for you? 

 

Ramon Norman 

Air Quality Engineer 

San Joaquin Valley Air Pollution Control District 

1990 E. Gettysburg Ave 

Fresno, CA 93726-0244 

Phone: (559) 230-5909 

FAX: (559) 230-6061 

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From: Deanne Meyer [mailto:dmeyer@ucdavis.edu] 

Sent: Friday, March 05, 2010 4:44 PM

To: Ramon Norman

Subject: RE: ::::RE: Silage Inoculants and Parameters or Practices to Reduce Emissions from Silage 

Hi Ramon, I just tried to call and got your voice mail. I had a lengthy discussion with our dairy nutrition extension specialist 

regarding silage fermentation etc. 

 

We did discuss the packing business and the methods needed to document sufficient packing==a laborious task at best. 

 

Let me know when a good time to phone is and I’ll give you a call Monday or Tuesday. 

 

From: Ramon Norman [mailto:Ramon.Norman@valleyair.org] 

Sent: Thursday, March 04, 2010 9:16 AM

To: Deanne Meyer

Subject: RE: ::::RE: Silage Inoculants and Parameters or Practices to Reduce Emissions from Silage 

 

Thank you for your help and I know that you are probably very busy. 

 

We are still learning quite a lot about silage production, but from the literature that I have read does point to 

sufficient packing (and moisture) as the key aspect for producing good silage and potentially reducing emissions. 

The latest recommendations have moved toward minimum bulk density (rather than dry matter density) to reduce 

gas-filled porosity (see http://www.uwex.edu/ces/crops/uwforage/Porosity-FOF.pdf and http://thefarmer.com/story.aspx/pack/silage/right/for/best/results/26/30931). Reducing porosity would directly reduce 

emissions from the pile by slowing transport of gases and would likely reduce the ethanol concentration in the 

silage. Our main question is what practices will ensure that silage piles are sufficiently packed. In our meeting 

we mentioned the University of Wisconsin Team Forage Spreadsheet as a potential tool to ensure adequate 

compaction of packing of silage: http://www.uwex.edu/ces/crops/uwforage/BunkDensCalc8-24-

07wPOROSITY.xls. However, many of the dairy representatives thought that it would not be feasible for the 

custom harvesters to use because of the time constraints. So any information you have on practices to ensure 

good packing of silage are appreciated. 

 

Thanks 

 

Ramon Norman 

Air Quality Engineer 

San Joaquin Valley Air Pollution Control District 

1990 E. Gettysburg Ave 

Fresno, CA 93726-0244 

Phone: (559) 230-5909 

FAX: (559) 230-6061 

 

 

 

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From: Deanne Meyer [mailto:dmeyer@ucdavis.edu] 

Sent: Thursday, March 04, 2010 8:50 AM

To: Ramon Norman

Cc: 'Paul Martin'; 'Paul Sousa'; Jim Swaney; Sheraz Gill; Sandra Lowe-Leseth

Subject: ::::RE: Silage Inoculants and Parameters or Practices to Reduce Emissions from Silage 

Ramon, I’m not in today and will review this tomorrow—along with your previous email. I’ve forwarded this to our dairy 

nutrition specialist and will check in with him before I reply. There’s a ton of literature on the inoculants---it’s a bit of a 

complex issue. My guess is that we’d have much better silage if people did a better job at packing their silage—versus using 

an inoculants. 

 

From: Ramon Norman [mailto:Ramon.Norman@valleyair.org] 

Sent: Wednesday, March 03, 2010 10:49 AM

To: Deanne Meyer

Cc: Paul Martin; Paul Sousa; Jim Swaney; Sheraz Gill; Sandra Lowe-Leseth

Subject: Silage Inoculants and Parameters or Practices to Reduce Emissions from Silage 

 

Hello Dr. Meyer, 

 

I hope you are doing well. In a recent meeting it was suggested that the District contact you to benefit from your expertise 

regarding the use of silage inoculants. The District is researching silage inoculation as a potential mitigation measure to 

reduce emissions of Volatile Organic Compounds (VOC) from dairy feed sources (silage piles and TMR) because the latest 

research studies have indicated that dairy feed is the largest source of VOC emissions at a dairy. We have found some 

literature on silage inoculants as a means to speed the drop in pH and increase lactic acid production and we would greatly 

appreciate any information that you can provide on the feasibility, effectiveness, and any effects on animal performance on 

dairies in California from the use of silage inoculants (e.g. homolactic LAB bacteria (like lactobacillus plantarum), 

heterolactic bacteria, addition of acidic material, etc.). 

 

Additionally, any information you have on practices or parameters to produce high-quality silage (e.g. moisture content, 

silage density, chop length, packing practices, pH, harvest rate, etc.) is also appreciated. We are really just starting to learn 

about silage production and management, but it appears that some of the goals of proper silage production and management 

also have the potential to reduce emissions to the atmosphere (e.g. increasing lactic acid, minimizing yeast, minimizing 

ethanol, better compaction, less porosity). So any ideas, general information, or references that you might have on producing 

high quality silage are also appreciated. 

 

Thanks 

 

Ramon Norman 

Air Quality Engineer 

San Joaquin Valley Air Pollution Control District 

1990 E. Gettysburg Ave 

Fresno, CA 93726-0244 

Phone: (559) 230-5909 

FAX: (559) 230-6061 

 

[attachment "SJVAPCD information on manure 2010.doc" deleted by Sona 

Chilingaryan/R9/USEPA/US] [attachment "manure heifers.pdf" deleted by Sona 

Chilingaryan/R9/USEPA/US] 

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