APPENDIX I SUPPORTING DOCUMENTS FOR AMENDED REVISED PROPOSED RULE 4570 (CONFINED ANIMAL FACILITIES) October 21, 2010 Final Draft Staff Report with Appendices For Amended Revised Proposed Amendments to Rule 4570
SAN JOAQUIN VALLEY UNIFIED AIR POLLUTION CONTROL DISTRICT Appendix I: Supporting Documents October 21, 2010 Appendix I Supporting Documents for Amended Revised Proposed Rule 4570 TABLE OF CONTENTS Document page Letter from Deanne Meyer, PH.D., UC Davis Livestock Waste Management and Peter Robinson, PhD., UC Davis Department of Animal Science Cooperative Extension, regarding Eliminating Silage, dated August 25, 2010 3 Letter from Dr. Frank Mitloehner regarding VOCs from feedlot calves, steers, and rations, dated August 15, 2010. 7 I-2 Final Draft Staff Report with Appendices For Amended Revised Proposed Amendments to Rule 4570
UNIVERSITY OF CALIFORNIA, DAVIS DEPARTMENT OF ANIMAL SCIENCE ONE SHIELDS AVENUE DAVIS, CALIFORNIA 95616.8521 TELEPHONE: (530) 752.1250 FAX: (530) 752-0175 Ramon Norman San Joaquin Air Pollution Control District August 25, 2010 Dear Ramon, You recently requested information to identify the cost and/or feasibility of eliminating silage from diets fed to dairy animals in the Central Valley. A brief overview of dairy cattle nutrition was provided at the meeting 8 July 2010 with US EPA held in Modesto. In brief, diets are formulated to provide various classes of dairy cattle with specific quantities of energy, protein, fiber, vitamins and minerals. Forage (herbaceous plants or plant parts consumed by animals such as pasture, hay, silage, dehydrated plants, and fresh green chop) is essential in the diet of ruminants and is a key contributor to dietary fiber quality and quantity. Preservation of herbaceous plants fed to dairy animals in California is primarily done through field drying (hay) or ensiling (silage). Feeding of ensiled forages in California began in the 1940 s and numerous research and demonstration projects were underway by the 1970 s. The improved feeding of animals resulted from introduction of ensiling technologies which in turn led to the introduction of totally mixed rations (which were not practical prior to the introduction of silage) and led to more efficient production of milk and the raising of replacement heifers. Ensiling is a technology that was introduced to preserve nutrients in the plant material that would subsequently be fed to cattle. For example, sugars in fresh cut plant material laid down to field dry will largely be consumed by continuing plant respiration (the plant continues to live after cutting until it dries out) and respired as CO 2. Sugars in fresh cut plant material preserved during the ensiling process will predominantly be converted to acetic, propionic and butyric acids. Although small amounts of these volatile fatty acids may volatilize, much of the carbon content will be consumed by the cattle and be be used as nutrients, primarily as a source of energy. It is common knowledge that properly ensiled feeds have higher nutrient value than their dried counterparts. Removing silage from diets of cattle would return California to less efficient production practices and turn the clocks of dairy management back more than 50 years. Removing silage from dairy feed will have widespread impacts. Dairy operators would have an unfair disadvantage to their counterparts out of state if feeding of silage was banned. Meeting dietary nutrient requirements of cattle will become difficult and will result in decreased milk yield and less efficient production. Reduced efficiency will increase environmental impacts. Dairy producers developed nutrient management plans with CVRWQCB to utilize manure generated nutrients in cropping systems. Utilization of a double crop system (corn and cereal grains) tends to recycle the largest quantity of nitrogen (N). Modifications to the nutrient management plan would require implementation of alternative cropping patterns and ultimately require more land for the same amount of N produced (since any other practical cropping pattern would use less N per acre). Few cropping patterns fit with dairy production to both utilize manure nutrients and generate feed for animal consumption. The latter is important to control costs of production. If additional land is not available to utilize manure N then manure will need to be
manifested off site. This may or may not be viable (location specific) and will most likely increase costs associated with manure management. Use of silage in diets provides highly digestible nutrients for the animal. There is no direct substitute for silage. It is often included in diets in relatively large amounts to provide animal nutritional needs and maintain rumen health. Substitution of alfalfa for part or all on the dietary silage would result in overfeeding N, increase N excretion and increase N volatilization as ammonia. Again, more land would be needed to manage manure N. Additionally, growing of alfalfa increases N fixation (imported into the watershed). Production of hay requires cutting, turning, baling and collecting bales. Volatiles will be emitted during the curing process. Replacing silage with feed by products and/or combinations of by products and grains will result in greater transportation needs. At some point, each California by product will be consumed leaving the need to import these feeds from out of state. This will increase costs of all feeds nationwide. It is unclear how much capacity is available for additional feeds to be imported. A finite number of loads of feed can be brought in to California via rail, especially in the winter when rail links can be weather impacted. Alfalfa is already purchased from out of state (i.e., NV, AZ, ID, UT). Importing nutrients and increased transportation should be considered before additional imports are required. Imported feeds bring in N and salts which will increase salt loading in the Central Valley, which is not desired by CVRWQCB. Costs of all feeds will go up because costs of hay and currently available commodities are interlinked. Removing existing feeds will impact the cost of all remaining feedstuffs. No doubt, the question which may be asked is: Why don t farmers simply field dry the corn and cereal plants and then feed them to cattle? Let s consider what feeding dried corn or cereal plants instead of ensiled materials might look like under San Joaquin Valley conditions. Planting Most probably a different configuration to planting rows of corn seeds will be needed in order to support the material at harvest (i.e., so that it does not rest directly on the soil which increases drying time). Current planting configurations of rows will be less desirable as some corn stalks would fall between the rows. The last possible planting date will need to be identified in order to allow growth, harvest and drying before temperatures change sufficiently to prevent field drying. Shortening the planting window will reduce cropping options from a manure nutrient recycling perspective, and reduce the ability of operators to control feed costs. Harvest The crop would dry out in the field and it is likely that some or even a lot (depending on wind speed) of the leaves (the readily fermentable fiber) of the corn would blow away. This would not likely be an issue with the cereal. Once dry, which would be a prolonged period of time for corn due to the thick and heavily cutin protected stem, the windrows would need to be picked up and chopped into trucks, more or less as is done now, except that this process would create a great deal of dust as small particles of the crop lifted into the air during chopping and blowing. Due to the light nature of the chopped material, some of it would blow away as well. Water Loss Water incorporated into plant material and included in animal diets contributes to animal daily water needs. Loss of this water (through drying) would require use of replacement water to meet animal drinking needs. In many locations within the San Joaquin Valley, irrigation water sources are from surface water supplies whereas cow drinking water is from groundwater supplies. Removing the incorporation of surface water (in silage) from animal consumption will require additional drafts of groundwater. Transport and Storage to Storage Piles
As the chopped crop material would now be dry and light, the weight loads of the transport trucks would be much reduced, and uncompacted, leading to more truck traffic to transport the material to the storage areas, where it would need to be unloaded and packed into large piles (more or less as is done now) except that the light material would be impossible to pack effectively and the piles would have to be much, much larger (width not height, as the material would not pack enough to allow equipment to work on it very high in the air) to accommodate the fluffy crop. This would lead to a sharp increase in the need for pad surface area, and a sharp increase in the amount of plastic used to cover the stored crop to prevent spoilage from wind, rain, etc. Additionally, this dry, porous material would be a rodent haven which could lead to feed contamination and compromised milk quality. Storage Pile Unloading This is difficult to envision since the piles would be very fluffy (not dense) and any semblance of a 'smooth face' or indeed a face of any kind would be eliminated. Unloading would create a very wide and deep unloading area that would blow badly in the wind leading to loss of material. The actual unloading at the face with the unloaders would create clouds of dust as the small particulates lifted into the air. The weight of dry matter carried by the unloader buckets would be less, leading to more unloaded loads to fill TMR mixers. The crop material would blow and fall off the unloader buckets both during transport to the TMR mixers and while being dropped into the TMR mixers. TMR Mixing and Loadout to the Bunklines The amount of dry feed weight that could be accommodated by the TMR mixers would go down as the density of the TMR's would go down. This would lead to more mixing time and more loads delivered to the bunklines. Again, this would add up to more vehicular trips to accomplish feeding cattle. As it has been shown numerous times that intake of TMR are maximized in the 40 to 50% moisture range and, in an effort to reduce dust and create some semblance of a homogeneous diet mixture, water would need to be added to the TMR's from sprayheads fitted over the TMR mixers, probably continuously to create even mixing (without added water to the TMR, it would be virtually impossible to mix and feed using current equipment, or really any equipment for that matter, as the rations would be very light and would blow badly in the wind as well as needing to be delivered numerous times per day). This would create a large new need for water on dairy farms (noted above). The loadout process to the bunklines would work more or less as it does now but, due to the less dense nature of the TMR, more loads per day would need to be delivered. Animal Response The ability of cows to sort and select within the TMR's would be sharply increased and this would lead to an increase in animal health problems, particularly acidosis and displaced abomasums, as cows sorted away from the coarse fibers (such as stems) that provide the structural fiber that stimulates rumination and saliva production. This new TMR would also lead to a sharp increase in the amount of feed that would not be consumed by the cattle, thus leading to an increased need to transport it back to the feed area for re mixing into other diets. Feed intake would decrease as the fermentability of the structural fiber, which is an important contributor to the net energy density of the TMR and a driver of voluntary feed intake, decreased. As the energy density of the corn and cereal crops would be lower, both due to the lower fermentability of the structural fiber and due to losses of sugars during the field dry down process to aerobic epiphytic bacterial and cellular respiration, attempts would be made by farmers to increase the energy density of the TMR's by adding more high energy feeds, such as grains, which would need to be imported by rail from the MidWest. However this would exacerbate the issue of sorting and acidosis noted earlier. Finally, due to the genetic drive of modern dairy cows to produce milk, even at the expense of their own bodies, the lactating cows would get thinner faster during lactation leading to poorer reproductive performance, lower milk yield, emaciation and higher death loss. In short, more cows would be required to meet current milk production levels, which would require yet more, and/or larger, dairy farms, and a higher proportion of the dietary net energy consumed by the cows being used to maintain the cows' bodies, and less used to produce milk. In short, nutrient efficiencies would decline on a larger total herd (if current milk production was to be sustained). Without silage as an option for San Joaquin Valley dairy farms, you can reasonably expect: 1) More dust 2) More vehicular emissions 3) More traffic on county roads
4) More concrete pads on farms and less arable land 5) Higher local feed needs due to reduced feed quantity and quality 6) Higher imported feed needs due to less local feeds 6) Reduced animal health and impaired animal welfare 7) Higher costs of all feeds nationwide 8) Higher costs of dairy products nationwide 7) Lower dairy farm profitability Feel free to follow up with additional questions. Sincerely, Dr. Deanne Meyer, Livestock Waste Management Specialist Dr. Peter Robinson, Dairy Cattle Nutritionist