ENVIRONMENTAL ISSUES IMPACTING THE NORTH CAROLINA
SWINE INDUSTRY: A SEARCH FOR SOLUTIONS
C.M. (Mike) Williams
Director, Animal and Poultry Waste Management Center
North Carolina State University
Box 7608
Raleigh, NC 27695-7608
During the past decade, much change has occurred in the composition of North Carolina's
agriculture. Due to growth in the state's swine and poultry industries, revenues from animal
agriculture now exceed those of crop production to reverse the historic relationship of these
two sectors. Between 1991 and 1996, the NC swine inventory increased from 2.7 million
head to approximately 8 million head. Most of the growth occurred in southeastern North
Carolina; in some southeastern counties the ratio of pigs to people is estimated to be
approximately 30:1. The economic benefits realized by the growth of the swine industry in
these counties and the State has been significant (Murphy and Hayes, 1994). However,
concerns and complaints associated with the increased volume and management of wastes
accompanying the growth of this industry has also been significant.
Concerns about the environmental impacts resulting from the rapid growth of the State's
swine industry resulted in legislation in both the 1993 and 1995 Sessions of the North
Carolina General Assembly. The primary focus in 1993 related to odor abatement issues
(North Carolina Agricultural Research Service, 1995). A lagoon failure in June of 1995 in
eastern North Carolina that resulted in the release of several million gallons of liquid swine
manure into the New River focused the public's attention on water quality issues.
Subsequently, the Blue Ribbon Study Commission on Agricultural Waste was created by the
1995 North Carolina General Assembly to study "the effect of agriculture waste on
groundwater, drinking water and air quality". Although the bill specifically noted
"agriculture waste" as its topic, the driving force behind the establishment of the
Commission was the rapid growth of swine production in the State, as well as the lagoon
failure referenced above. The majority of the documents reviewed, testimony heard, and
recommendations made by the Commission centered around swine production practices
(Blue Ribbon Study Commission on Agricultural Waste, 1996). During the past year the
North Carolina Department of Environment, Health and Natural Resources has offered free
analysis of drinking water wells proximate to large livestock farms. Recent data shows that
of nearly 1000 wells tested, approximately 10% exceeded nitrate-nitrogen concentrations (10
ppm) considered safe for drinking. It is likely that this issue will be a topic of discussion
during the upcoming 1997 legislative session.
North Carolina is not unique in its attention directed to waste management practices of the livestock industry in general and swine industry in particular. Several states are considering regulatory changes that have the potential to significantly impact the future of animal agriculture. Much of the increased focus on animal agriculture can be attributed to the urbanization of traditionally agricultural areas and the resulting conflicts between food-animal producers and the general public regarding odor issues. In many areas, nuisance concerns associated with odor may impact the sustainabilty of animal agriculture more so
than water quality issues.
There is little doubt that alternative strategies for mitigating environmental impacts resulting
from the production, storage, treatment and/or land application of livestock waste will be
required in the future. As noted recently by The University of Georgia Cooperative
Extension Service (AWARE NEWS, 1996), "Technology, which has been a major factor in
concentration of the livestock and poultry industry, may also be the key to manure
management in the future". North Carolina State University (NCSU) concurs with this
position and has established a program such that academia, industry, commodity, economic
development and environmental interest groups, as well as government agencies may form
interactive partnerships to address common goals and objectives regarding environmental
concerns associated with animal agriculture. Since 1994, this program, the Animal and
Poultry Waste Management Center (APWMC), has sponsored efforts in three primary areas:
The APWMC's organizational approach is broad based and multidisplinary. Projects
currently supported involve over 30 NCSU faculty from 10 different departments within
the College of Agriculture and Life Sciences (CALS). In addition, the APWMC is
participating in research projects involving other colleges within NCSU and other
universities within and outside the state, as well as research institutions in Europe. It is
anticipated that the deliverable technology and management practices that result from these
partnerships will provide tremendous economic and environmental impacts which will
enhance the sustainability, productivity, and profitability of the state and nation's animal
agriculture industries. To follow is an overview of APWMC activities.
APWMC OVERVIEW, 1994 - 1996
Numerous processing procedures for animal agriculture co-products have been proposed by
researchers at many institutions in the U.S. and abroad. However, many such alternatives
have not been evaluated or demonstrated beyond the laboratory on a commercial or full scale
basis by the investigators conducting waste management research and extension work due
to the lack of infrastructure to do so. The APWMC facilities (existing and planned) are
housed on approximately 5 acres at the NCSU Agricultural Field Laboratory located
approximately 8 miles south of the NCSU main campus. Two buildings--a waste processing
equipment building (currently being equipped) and a composting building (construction
scheduled for 1997)--will provide facilities and equipment necessary for research,
development, outreach and demonstration of advanced waste management technologies. In
addition, NCSU's poultry, swine and dairy and cattle research units, located on adjacent
property, will supplement the APWMC facilities. Collectively, these facilities and a research
laboratory located in Scott Hall on the main NCSU campus provide the current APWMC
infrastructure.
The APWMC, however, is not a facility as much as it is an organizational concept. In order
to efficiently and effectively address the waste management requirements of the food-animal
industries, a broad based and interdisciplinary participation and input into the APWMC
activities is needed. The APWMC has, therefore, established an operational structure in
which various groups with an interest in animal agriculture form a partnership to address the
agricultural food-animal waste management research area.
A SEARCH FOR ALTERNATE TREATMENT
AND UTILIZATION TECHNOLOGIES
Some key research, development, and education areas related to water and air quality that are
planned and/or are currently being addressed by the APWMC include the following:
Nutrient management presents a significant challenge to the food-animal producer. Poor
management by one or a few producers can have widespread impacts on the entire industry
regarding perception and potential regulations. Nutrients contained in waste products such
as manure slurry or litter can be cycled from crops to feedstuffs to animals to soil and again
to crops. Under proper management practices, this cycle can be maintained under
economical and environmentally sound conditions. This includes analysis of the manure
content for fertilizer value, uniform application rates to the soil at times of the crop growing
cycle such that uptake is maximized, and subsequent adjustment of commercial fertilizer
rates, etc. Other alternatives include the development of products for which there may be
specialized or niche markets suitable for utilizing the nutrients contained in manures. This
would enable the movement of nutrients away from areas of intense livestock and poultry
production and provide a cash return to the producer as well.
Examples of APWMC research in progress to meet these objectives include (listings include
project title and principal investigator): A system for the development of value-added
products from swine manure and peanut shells, E. E. Jones; Recovery of solids from flushed
swine manure for utilization, P. W. Westerman; Genetically engineered microorganisms for
utilization of ammonia and other nitrogenous compounds from animal manure, E. E. Jones;
The use of poultry litter as a co-substrate and source of inorganic nutrients and
microorganisms for the ex situ biodegradation of hazardous compounds, C. M. Williams;
Evaluation of fluidized-bed drying technology for recycling poultry litter as bedding material,
C. M. Williams; Separation of turkey litter to enhance its value as a cattle feed ingredient,
J. L. Grimes; Deep stacked broiler litter as a protein supplement for dairy replacement
heifers, B. A. Hopkins; Predicting nutrient release from food and animal waste products, R.
L. Mikkelsen.
In many cases, food-animal mortalities (especially for poultry and young swine) are currently
being buried in on-farm pits. This practice may degrade water quality, at least in areas with
certain soil types and/or high water tables, so alternatives must be developed to manage and
recycle these potentially valuable co-products. Over the past few years, a number of poultry
enterprises have begun utilizing the natural biological process of composting to handle their
animal mortalities. This process provides a good, relatively low-cost alternative for
disposing of animal mortalities in an environmentally safe manner but still results in a
product that must be land applied. Thus, alternative systems need to be developed,
demonstrated, and refined which will allow on-farm preservation and storage of the
preserved carcasses so that larger quantities can be collected and transported to rendering,
drying and/or extrusion facilities for conversion into animal feed-grade meals.
Offal from food-animal processing plants has for many years been sold to rendering plants
for conversion into feed-grade meat, bone and blood meals. Feathers, another major co-product of poultry processing plants, have been hydrolyzed and converted into feed-grade feather meals. A number of what would appear to be economically viable and better
alternatives such as acid fermentation, fluidized bed drying, extrusion, and treatment with
newly developed enzymes, have been introduced over the past few years, but these
alternatives need to be scaled up and possibly modified so they can be demonstrated to be
economically feasible and viable, if they are to become adopted by the animal industries.
Examples of APWMC research in progress to meet these objectives include: Development
and demonstration of a fermentation-preservation system for converting poultry mortality and
sweet potatoes into value-added products, P. R. Ferket; Optimizing the proteolytic
degradation of animal by-products, E. S. Miller; Conversion of ensiled poultry, fish, and
sweet potato byproducts into high value poultry and aquaculture feed ingredients, P. R.
Ferket; Composting--turning swine carcasses into humus, W. E. Morrow; Production of
amino acids and peptides from feathers and other proteinaceous wastes using immobilized
keratinase, J. C. H. Shih.
One of the more sensitive environmental issues currently facing the food-animal agriculture
industry in general, and the pork producers in particular, is odor control. Numerous odor-control technologies have been developed for various industries that generate odorous compounds. However, many of these technologies are not considered to be technically or
economically feasible for most livestock and poultry operations. Further research and
development, as well as outreach demonstration of their economic and environmental
benefits will be required prior to their widespread utilization in the food-animal production
industry. Several APWMC projects are targeting odor control, and the approach, in most
cases, will also address water quality issues. Examples of these projects include: Biofilter
for removing odorous compounds in exhaust from swine buildings, J. J. Classen; Utilizing
by-products to clean air in swine buildings, R. W. Bottcher; The potential of thermophilic
anaerobic fermentation for biological methane production and odor control using swine
manure as a substrate, C. M. Williams.
In addition, cooperative efforts were established between the APWMC, other universities,
commodity groups, and commercial enterprises to establish a testing procedure and reporting
format which can be used to provide consistent odor product information for food-animal
producers and processors. The protocol developed through these efforts has been utilized
by the APWMC to evaluate the effect of several products (laboratory and commercial scale
analysis) on odor intensity, odor irritation, odor quality and other environmental parameters
associated with swine manure.
A logical approach to reducing the environmental impacts of nitrogen, phosphorus, copper,
zinc, and other elements in manure is the improved efficiency of utilization of these nutrients
by the animal. More work is needed to "fine tune" the nutritional requirements of food-animals as they relate to environmental issues as well as consumer requirements for meat, eggs, and milk. The efficacy of using exogenous enzymes in animal feedstuffs for improved
utilization of oligosaccharides, phytate, and selected proteins needs to be determined. The
effect of new feed processing technologies (dryers, extruders, expanders, etc.) on co-product
nutrient availability and digestion also needs to be determined. Plans are underway for the
APWMC to actively support such research efforts in the near future. One example is support
of the project: Genetic control of nutrient utilization in swine, O. W. Robinson (initiated in
1996).
Other projects that have been initiated during the previous 3 years to support the APWMC
objectives include: Molecular phylogenetic survey of methane-producing archaea, J. W.
Brown; Development and demonstration of an integrated wastewater and processing waste
management system for trout production, J. E. Shelton; Evaluation of wetland plant species
for use in constructed wetlands, J. M. Stucky; Management of field buffers to improve water
quality in watersheds receiving swine lagoon effluent, R. L. Mikkelsen.
DEMONSTRATION OF ALTERNATE TREATMENT
AND UTILIZATION TECHNOLOGIES
As technology advances the economic and environmental benefits of co-product utilization,
it will be necessary to demonstrate on a commercial scale, the technical, economic, as well
as social feasibility of the various technologies. An agreement was recently established
between the APWMC and the North Carolina Department of Environment, Health, and
Natural Resources to provide resources by which innovative technologies, developed by
research institutions and/or the private sector, targeting food-animal water quality issues may
be evaluated and demonstrated on the sites of cooperating producers, university or NCDA
research farms. This program is currently in the start-up phase. A total of 11 projects have
been selected and research efforts are expected to be actively underway during the Spring of
1997. The program will result in several demonstration sites, primarily located in eastern NC
where the alternate treatment and utilization technologies will be evaluated for their
environmental deliverables, capital and operating costs, and technical requirements for day
to day operation. Selection of the technologies for evaluation were based on evaluations and
critical reviews by a team represented by: 1) out of state scientists, 2) NCSU research and
extension faculty, and 3) an Advisory Committee made up of representatives from research,
extension, NC regulatory, commodity and environmental interest . It is also planned for
these same groups to be involved in the evaluation process.
Interaction, communication and partnerships between the parties noted above will result in
efficient identification of real and emerging environmental issues and subsequent solutions
to address issues concerning waste management. It is essential that we not only pool our
resources and talents, but also involve representation of all aspects of society that will be
impacted by the production and processing of livestock and poultry.
REFERENCES
AWARE NEWS-Animal Waste Awareness in Research and Extension. 1996. The
University of Georgia Cooperative Extension Service. Volume 1, No.2, p. 11.
Blue Ribbon Study Commission on Agricultural Waste. 1996. Report to the 1995 General Assembly of North Carolina, 1996 Regular Session.
Murphy, B. and C. Hayes. 1994. North Carolina Agricultural Statistics. D. G. Watson (editor) Published by North Carolina Agricultural Statistics, Raleigh, NC.
North Carolina Agricultural Research Service, J. C. Wynne, Director. 1995. Options for managing odor. A report from the swine odor task force.
Back to Title Page