Raising Hogs in the Information Age

By Drs. Mark J. Estienne and Allen F. Harper Virginia Tech Tidewater Agricultural Research and Extension Center (TAREC) Suffolk, Virginia
calendar icon 26 March 2007
clock icon 13 minute read


Prior to the 1970’s, pork production was often considered a secondary farming enterprise, typically associated with grain production. Swine were kept outdoors or had access to only modest shelters. Labor-intensive production systems were generally designed such that all sows on a farm farrowed as a group, one or two times each year. Pigs were weaned at 6 weeks of age and natural mating systems predominated.

Today, however, pork production is largely a primary, “stand-alone” enterprise. Although there has been a recent increase in the number of outdoor swine producers niche-marketing pork to consumers that prefer this method of production, most hogs in the U.S. are raised indoors in total confinement facilities. Sow herds are subdivided into groups and farrowing, weaning, and breeding activities occur each week of the year. Pigs are generally weaned at less than 21 days and the majority of sows and gilts are bred using artificial insemination. Indeed, today’s pork production is management intensive and relatively sophisticated.

The swine industry, however, continues to rapidly change and producers are faced with a burgeoning amount of information relative to pork production. In order to remain viable, today’s pork producer must keep abreast of new developments and when appropriate, adapt and incorporate new methods and technology into their production systems. In addition to advances in husbandry techniques, producers must also be keenly aware of major issues that could potentially impact their operations.

A swine producer’s decision to change a husbandry practice or production system and response to emerging issues should be based on high-quality information most often derived from sound, scientific research. Ultimately, consumers have a major impact on the pork production chain, so there is an obvious need to educate, and provide reliable information to, the public as well.

The objective of this paper is two-fold. First presented is a brief overview of what the authors consider to be some of the most important issues and areas of research (in no particular order) in the area of pork production and management; Where appropriate we present pertinent references to research conducted at the TAREC swine research facility. Second, we provide a guide for those wishing to obtain sound information on which to base decisions that impact the production of pork.

Important Issues and Areas of Swine Research

Impact of Ethanol Production on Swine Production. The portion of the U.S. corn crop used for ethanol production was less than 5 percent 10 years ago, but greater than 20 percent in 2006. The U.S. currently has 100 active ethanol plants that can produce over 5 billion gallons of ethanol each year. An additional 58 plants are under construction or are being expanded. Another 150 ethanol plants have been proposed. It is apparent that the ethanol industry will compete with the livestock and poultry industries for corn and at least in the near term, impact swine production by causing higher feed costs. According to economists at Iowa State University, the growing demand for corn used in ethanol production in the U.S. has already increased the costs of hog production by approximately 10 percent. Ongoing research in the U.S. is evaluating alternative feedstuffs for use in swine production, including distiller's dried grains with solubles (DDGS), a co-product from plants that produce ethanol for oxygenated fuels.

Swine Welfare. Production systems and husbandry techniques employed on U.S. farms, and potential effects on swine welfare are under ever-increasing scrutiny by the American public. Public perceptions and misconceptions of welfare issues have the potential to dramatically impact swine production if governments, the swine industry, or consumers react to these issues by banning housing systems, mandating changes in husbandry practices, and/or boycotting pork. For example, amendments to the constitutions of Florida (2002) and Arizona (2006) were passed by voters that prohibit pregnant sows in those states from being confined in individual gestation stalls. In reality, Florida and Arizona are small states in terms of pork production and the bans will impact only a handful of commercial farms. Never-the-less, the amendments could set a precedent for pork production and other states with larger industries, such as Virginia, could conceivably follow suit. In determining whether or not swine welfare is compromised, individuals may act emotively and perhaps without factual biological information. Research in the U.S. is both ongoing and needed in several areas of swine welfare including the development of methods to assess the actual “well-being” of animals on the farm, methods of quantifying stress, segregated early weaning, animal handling and transportation, on-farm euthanasia, animal space requirements, and sow housing.

In the U.S., the majority of gestating sows are housed in stalls that physically limit animals to standing, sitting, or lying. This severe restriction of freedom of movement has been robustly criticized by animal right activists and the gestation stall issue is one of the most contentious facing the swine industry. Based on a review of the scientific literature, it can be concluded that stalls or well-managed pens in which sows are group-housed, generally (but not in all cases) produce similar states of welfare in terms of physiology, performance, and health. At TAREC, Estienne et al. (2006) reported that specific indicators of welfare were differentially affected by type of gestation housing (gilts kept individually in gestation stalls or in groups of three gilts each). Group-housed gilts gained more weight, had more injuries and a higher incidence of lameness. Gilts kept in gestation stalls had higher blood concentrations of cortisol (a classical “stress” hormone), but a higher pregnancy rate. There was no effect of type of gestation housing on backfat thickness, behavior, ovulation rate, or litter size. When considering all measurements recorded in this comprehensive study, Estienne et al. (2006) concluded that overall welfare was similar for gilts housed in stalls or in groups.

Swine Health and Diseases. Although numerous diseases cause economic loss to swine producers, the two that are currently of most concern are Porcine Reproductive and Respiratory Disease (PRRS) and Porcine Circovirus Associated Diseases, formally called Post-weaning Multisystemic Wasting Syndrome (PMWS).

PRRS was first described in the U.S. in 1987. In the breeding herd, the virus causes abortions and in newborn pigs, respiratory distress and death losses of up to 100%. The economic impact of PRRS in a breeding operation during the year of an outbreak has been estimated to be as high as $110 to $240 per female. In nursery pigs, PRRS causes increased death loss and decreased growth rate and feed conversion efficiency. Increases in treatment costs can exceed $1.75 per pig.

Porcine Circovirus Associated Diseases is an emerging health issue in Virginia as well as across the U.S.; Swine producers are gravely concerned. At 6 to 8 weeks of age weaned pigs loose weight and gradually become emaciated with rough hair coats and pale skin. Death loss is usually 6 to 10 percent but can be as high as 20 percent. Active disease in a grower-finisher unit can cost a producer more than $6 per pig. A review of Circovirus and related diseases by L. Karriker appears elsewhere in these proceedings. Potential Impacts of Swine Production on the Environment. The potential, adverse effect of swine production on the environment continues to be an issue of great interest. Research at universities throughout the U.S. is focusing on the mitigation of possible negative impacts of rearing hogs on air and water quality, odor control, manure nutrient management and on-farm mortality disposal.

In Virginia, manure nutrient management plans must now consider phosphorus, which considerably increases the amount of land necessary for disposal of swine effluent. In research conducted at TAREC, Harper et al. (1997) demonstrated that growing-finishing hogs consuming diets low in phosphorus but containing the enzyme phytase excreted 21 percent less phosphorous into the environment compared with hogs consuming a diet with adequate levels of phosphorous; Growth performance also favored animals fed the diet containing phytase. Results of this study were used by an integrator in Virginia in applying for a grant to install phytase application equipment in the feed mill and the enzyme is currently being used in swine feeds throughout the state with positive results.

Even on the best-managed hog farms, swine die and must be disposed of. On-farm burial or incineration has potential environmental consequences and access to renderers is limited in many states including Virginia. Research conducted at several universities as well as at TAREC (Harper and Estienne, 2003) has indicated that composting is an effective method of mortality disposal when properly carried out and offers many possible advantages when compared to other alternatives. The number of swine farms in Virginia using this technology is increasing.

Potential Resistance to Antimicrobials Used in Swine Production. Efficient and profitable operation of commercial swine units is often limited by high mortality, morbidity, and poor performance in the nursery and growing-finishing phases of production. Antibiotics are routinely used on U.S. swine farms and are administered in the form of medicated water or as feed additives. The addition of antimicrobial products to nursery feeds is especially effective with typical improvements in growth rates and feed conversions efficiencies of up to 16 percent and 6 percent, respectively. Industry surveys suggest that more than 82 percent of U.S. swine farms with nursery pigs use antimicrobial feed additives in diet formulations. Because of the concern that resistant microbes may develop that compromise the effectiveness of antibiotics for treating human and animal diseases, the routine use of antibiotics on commercial hog farms faces an uncertain future. For example, the U.S. Food and Drug Administration has called for an extensive re-evaluation of continued use of antimicrobial feed additives. Thus, research at several sites, including TAREC (Estienne et al., 2005; Harper and Estienne, 2002), is being conducted to evaluate alternatives to traditional antimicrobial growth promoters.

Gleaning Information for the Pork Industry

Importance of the Information Age. The preceding analysis of selected issues facing the swine industry makes one point very clear. There is a tremendous amount of information that people involved in the production of hogs must keep aware of. Just taking care of the day-to-day activities required in producing hogs is a full time effort. So the challenge seems to be staying abreast of important developments and new information while under the demands and time constraints associated with raising hogs. It is tempting to focus only on the day-to-day tasks of raising hogs and let awareness of new information take care of itself. Such an approach, however, is naïve and will not allow for sustained effectiveness in hog production. Simply put, the business of raising hogs will continue to evolve and change at a rapid pace. Those who fail to keep abreast of new information and developments (as well as established technologies that apply to their situation) will find themselves behind and struggling to catch up.

The “information age” is a loosely defined term referring to the period that began after the “industrial age.” The Wikipedia free encyclopedia defines the information age as the period that began once the movement of information became faster than physical movement of goods and services, or roughly around the 1980’s onward. Certainly expanded use of computers and the internet were major components of this. Now that information transfer is so fast and widespread, terms like “knowledge economy” and “intangible economy” are replacing the so-called information age economy. The truth is the information age has not gone away, but hopefully the efficiency with which we access, process, interpret and apply information is improving. This applies to all enterprises, including the business of raising hogs.

The Right Approach to Information Access and Use. Another modern-day term associated with the information age is “lifelong learning.” The concept implies that it is never too soon or too late to learn new things. Effective lifelong learning requires a certain attitude and of course, a desire to seek out new information and knowledge. At least three characteristics can be ascribed to effective lifelong learning. These include:

  • Making it a priority to routinely take time to access, evaluate and learn from new information.
  • Being “open minded” about new ideas and information. However, this does not mean being gullible and accepting all new information without question, thought and careful consideration.
  • Being a “critical thinker” without being cynical. When a cynic considers new information or an idea, the first reaction is usually negative and the attitude is “that will never work” or “that is hogwash.” However, a critical thinker evaluates new information carefully and objectively, determines its potential weaknesses and strengths and under what conditions the information might be most useful.

Example Sources of Information for the Pork Industry. Conferences, seminars, workshops and production meetings are definitely valuable sources of useful swine production information. But routine use of information usually involves regular access to publications, newsletters or websites. The following table provides an abbreviated list of example sources of information for those involved in swine production and the pork industry. The listing is not all inclusive and producers are encouraged to seek out other sources that may be useful to them.

Table 1. Example Sources of Current Information for the Swine Industry*

Source: Description: Comment:

Pork Information Gateway


A website with over 200 expert reviewed fact sheets and other publications. Questions may be submitted for swine specialists to address.

There is no monetary cost to access information in this site. For full access free registration is required and the site has numerous links to other swine related organizations and university departments.

electronic newsletter


An industry website that gleans current information daily for distribution to subscribers.

A subscription fee based service.
Annual subscription fees for an individual currently listed at $359.40.



A website with a variety of swine production related topics and links.

Based in Britain but has considerable focus on North America. Free access, supported by advertisering. Registration (free)required to access certian features.

PCV2 Homepage


Iowa State Univ. College of Veterinary Medicine website dedicated to
Porcine Circovirus Type 2.

See paper in these proceedings on PCV2 by Dr. Locke Karriker.

Virginia Department of
Environmental Quality
Agriculture Webpage


Provides information on DEQ programs related to AFO and CAFO permitting and other links related to manure and waste management on farms.

Has links for mortality disposal and other waste management practices.

The New Pork Industry Handbook

A technical publication
containing 184 fact sheets written and reviewed by swine experts throughout the country. Available in DVD or hard copy.

Maintained and sold by Purdue University Agricultural Publications (765-494-6794)

National Hog Farmer

Industry Trade Magazine

Pork producers can subscribe at no charge (866-505-7173)

Pork magazine

Industry Trade Magazine

Pork producers can subscribe at no charge (866-647-0918)


Weekly publication for the livestock feeding industry

Subscription rates are $144 per year. (1-800-441-1410)

Journal of Swine Health
and Production


Swine Veterinary Science Journal Published by the American Association of Swine Veterinarians.
Articles report on research and case studies.

Full text articles are available only to members or subscribers. Abstracts are searchable on-line by title.

Journal of Animal Science


Scientific publication of the American Society of Animal Science.

A topical search engine is available on the publication’s website and pdf versions of the full text articles are available.

* The sources listed are for example purposes and other information sources exist. Listing a source in this table does not imply superior value nor does not listing a source imply lesser value.

TAREC References

Estienne, M.J., A.F. Harper, and J.W. Knight. 2006. Reproductive traits in gilts housed individually or in groups during the first thirty days of gestation. Journal of Swine Health and Production. 14:241-246.
Estienne, M.J., T.G. Hartsock, and A.F. Harper. 2005. Effects of antibiotics and probiotics on suckling pig and weaned pig performance. International Journal of Applied Research in Veterinary Medicine. 3:303-308.
Harper, A.F., and M.J. Estienne. 2002. Efficacy of three potential alternatives to antimicrobial feed additives for weanling pigs. The Professional Animal Scientist. 18:343-350.
Harper, A.F., and M.J. Estienne. 2003. Composting for mortality disposal on hog farms. Virginia Cooperative Extension Publication 414-020.
Harper, A.F., E.T. Kornegay, and T.C. Schell. 1997. Phytase supplementation of low-phosphorus growing-finishing pig diets improves performance, phosphorous digestibility, and bone mineralization and reduces phosphorus excretion. Journal of Animal Science. 75:3174-3186.

March 2007
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