ECONOMIC COST OF MAJOR HEALTH CHALLENGES IN LARGE US SWINE
PRODUCTION SYSTEMS - PART 1

Derald Holtkamp, DVM, Iowa State University, Ames
Hans Rotto, DVM, Innovative Agriculture Solutions, Ames, Iowa
Roberto Garcia, DVM, Merial Ltd., Duluth , Georgia

Introduction
Estimates of the economic impact of specific diseases on the U.S. swine industry are available for very few diseases. Recent research estimated the annual cost of PRRS in the U.S. to be approximately $560 million.1 However, more comprehensive estimates of the impact of all major health challenges have not been published . A comprehensive estimate of all major swine health challenges is needed to facilitate industry benchmarking and to help guide animal health related investments in the industry. The objective of this study was to rank and quantify productivity and economic losses in the swine industry due to the major health challenges. Information on production and economic impacts was obtained through use of face-to-face, personal interviews. The focus of the study was on the segment of the U.S. industry producing more than 150,000 pigs per year. This segment currently markets just under half of the pigs sold annually in the U.S.

Materials and methods
The companies producing more than 150,000 pigs per year were identified. This population of companies was further segmented by size, vertical integration, and geographic location in order to assure representation of the entire population of interest. Production companies with 7,500 to 25,000 sows were considered "medium" sized while companies with more than 25,000 sows were considered "large." Vertically integrated companies for the purposes of this project were defined as those that have integrated live animal production, slaughter, and processing. Only companies with more than 25,000 sows were segmented as integrated or not integrated since very few producers with fewer than 25,000 sows are vertically integrated. The U.S. was divided into three geographic regions based upon USDA's 10-region classification. The groups are East (Appalachian, Delta, Northeast, Southeast), Midwest (Cornbelt, Lake States), and West (Northern Plains, Pacific Northwest, Southern Plains, Mountain). This segmentation scheme resulted in nine segments (Table 1) . Two production companies from each of the nine segments were selected for inclusion in the study. A third medium-sized company in the West was surveyed for a total of 19 surveys. When production companies had major operations in more than one geographic location, each location was considered a separate entity. Selection of companies was based on the anticipated willingness to participate and availability of interviewees during the timeline of the project and, therefore, not random. Only one company asked to participate declined.

A survey was developed and administered to a single veterinarian at each company through face-to-face, personal interviews. The same interviewer administered all of the surveys in a consistent manner to minimize any differences in the results attributable to differences in how the surveys were administered. All of the surveys were conducted between November of 2005 and February of 2006.

Results
The relative rankings for each of the health challenges are reported here. The ranking of health challenges according to the productivity losses attributed to each in the breeding, nursery, and finishing herds are reported in Figures 1, 2 and 3.

Breeding herd
In the breeding herd, PRRSV was the most frequently ranked health challenge (Figure 1). It was ranked as a health challenge resulting in productivity losses in the breeding herd for 18 of the 19 companies surveyed. Further, it was ranked as number one (1 being the health challenge with the greatest productivity losses) in every one of the 18 companies that ranked it. PRRSV was also ranked as a health challenge in combination with Salmonella and PCV2 by 2 companies. Swine influenza was ranked as often as PRRSV and with the second greatest productivity losses (average rank of 3 .7) when ranked. Swine influenza in combination with PCV2 was also ranked 11th by one company.

Clostridia l diseases as a group were identified as the next most significant health challenge in the breeding herd . Clostridium perfringens type A was ranked as a health challenge in IS of the 19 companies with an average rank of 4.1, Clostridium difficille ranked in 9 of the 19 companies with average rank of 7.1, and Clostridium perfringens type C ranked in 4 of 19 companies with average rank of 5.8. Rotavirus alone or in combination with E. coli was cited as a breeding herd health challenge for IS of the 19 companies. As a single pathogen it was cited as a health challenge in 10 companies with an average rank of 5.3. In combination with E. coli, rotavirus was cited as a health challenge for 7 companies with an average rank of 4.9, higher than that of rotavirus alone. Streptococcus suis and Coccidia were cited as a health challenge for 14 and 12 companies with an average rank of 7.0 and 6.0, respectively lIeitis and Mycoplasma hyopneumoniae were ranked for 13 and 12 companies with an average rank of 6.2 and 7.3, respectively. The last three on the list of health challenges in the breeding herd cited for more than half the companies were greasy pig disease, E. coli. and Haemophilus parasuis.

Nursery herd
In the nursery herd , PRRSV was the most frequently ranked health challenge (Figure 2). As in the breeding herd, it was ranked as a health challenge in 18 of the 19 companies surveyed and was ranked as the number one health challenge in all but one of the 18 companies in which it ranked. PRRSV was also ranked as a major health challenge in combination with Salmonella and PCV2 for 2 companies. Haemophilus parasuis and swine influenza were also ranked as a health challenge for 18 of the 19 companies with an average rank of 4.1 and 4.3. Swine influenza also ranked as health challenge in combination with PCV2 for one company. Streptococcus suis was cited as a health challenge for 17 of 19 companies with an average rank of 4.1. E. coli was ranked for IS companies with an average rank of 5.2. Greasy pig, Mycoplasma hyopneumoniae, Pastuerella multocida, and Bordatella bronchiseptica complete the list of health challenges cited for more than half the companies. PMW, PRRS in combination with PCV2, and SIV in combination with PCV2 were all cited as nursery problems in a small percentage of the companies surveyed, but when cited, the productivity losses associated with them were ranked relatively high . At the time the surveys were completed, Porcine Circovirus Associated Diseases (PCVAD) had not yet been adopted.

FOOT-AND-MOUTH DISEASE UNDER STUDY

A nation wide research study aimed at protecting the livestock industry from the devastating consequences of foot-and-mouth disease has been launched in California.

All U.S. livestock producers have been asked by the Center for Animal Disease Modeling and Surveillance (CADMS) in the School of Veterinary Medicine at the University of California at Davis to participate in an online survey on animal movements and husbandry practices. The data gathered will be used in a simulation model to predict the duration and magnitude of a foot-and-mouth disease (FMD) outbreak, as well as determine the best strategies for containment.

The project is being conducted in collaboration with the National Center for Foreign Animal and Zoonotic Diseases (FAZD ) and is supported by the U.S. Department s of Agriculture and Homeland Security.

FMD is one of the most highly contagious diseases affecting cloven-hoofed animals, such as cattle, swine, sheep, goat s, and deer. In 2001 an outbreak in the United Kingdom resulted in the slaughter of at least 6 million animals and catastrophic economic losses of more than $15 billion. In the U.S., the economic impact of such an outbreak could go as high as $13 billion and affect every segment of the livestock industry.

FMD is at the top of the Department of Homeland Security 's list for a bioterrorist attack on U.S. agriculture.

"Because it spreads so quickly and is easily transmitted, the threat of FMD to the U.S. is very serious, and we need to be prepared," said Dr. Tim Carpenter, director of the study. "Our model will provide decision-makers with a valuable too l for rapid response and will help determine the best strategies, including vaccination, to contain an outbreak and minimize impact to the livestock industry."

With no cases of FMD in the U.S. since 1929 to use as an example, it is hard to predict how an outbreak might spread in today 's global environment. Information about the distribution of livestock nationwide, animal movements, and husbandry practices in the U.S. is not up to date . This lack of information hampers the implementation of an effective response strategy.

Dr. Carpenter said, "The online survey will allow us to develop a model based on real, up-to-date data for animal movements and current practices that could determine how the disease spreads. Only livestock producers can pro vide us with this information. This model would put the U.S. at the forefront in preparedness for not only foot-and-mouth, but also other foreign animal diseases."

CADMS guarantees that all information will be kept confidential and used only for modeling purposes. The online survey can be found at: http://www.cadms.ucdavis.edu. North Carolina livestock producers are encouraged to participate. For more information, contact Pelayo Alvarez at (530) 554-2988.

- Submitted by Todd See