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Respiratory diseases represent one of the main health issues facing modern pig farms. In addition to affecting productivity, they also negatively influence the welfare status of pigs.
They cause considerable losses to farmers, due to a variety of factors:
- The increased time it takes for pigs to reach slaughter: this leads to a subsequent increase of feed intake, and a longer time in which pigs occupy farm facilities.
- Higher levels of pig mortality: studies carried out by the United States Department of Agriculture in 2006 and 2012 found respiratory conditions to be the leading cause of mortality in nursery and grower/finisher pigs in the country.
- Increased veterinary expenses: respiratory disease leads to a more extensive use of veterinary treatment and vaccinations.
What causes respiratory diseases of pigs?
Respiratory diseases of pigs are generally caused by the interaction of several interrelated factors. A poor piggery environment contributes to a lowering of pigs’ immune defenses, making them more susceptible to respiratory pathogens.
Specific causative agents
Respiratory diseases of pigs are generally characterized by a complex etiology – meaning the cause of disease – involving viruses, mycoplasmas, and bacteria, in addition to managerial factors.
They are thus often considered collectively as the “Porcine Respiratory Disease Complex” (PRDC).
Some of the principal agents involved in PRCD are listed below:
- Viruses: porcine reproductive and respiratory syndrome virus (PRRS); porcine circovirus type 2 (PCV2); swine influenza virus (SIV).
- Bacteria & Mycoplasmas: Mycoplasma hyopneumoniae; Actinobacillus pleuropneumoniae; Actinobacillus suis; Pasteurella multocida; Streptococcus suis; Glaesserella parasuis.
Management strategies to control respiratory diseases on your pig farm
As respiratory diseases of pigs are complex and multifactorial, the strategies to manage them must be well thought out.
A few fundamental managerial aspects which can improve the respiratory health of pig herds are discussed below:
- Farm environment: ventilation and temperature in barns must be well managed. Dusty or dirty facilities, or those with high levels of ammonia or excessively hot or cold barn temperatures or drafts lead to a reduction of pigs’ immune defenses, making them more susceptible to respiratory pathogens.
- Introduction of new pigs onto the farm: the highest probability of introduction of a new pathogen onto a farm comes with the arrival of new animals. Therefore, the introduction of pigs, especially those with an unknown health status, should be avoided whenever possible. In the case of necessary purchase of new pigs to be introduced into a herd, strict quarantine procedures should be followed.
- Avoid pig mixing: even within a farm, strict separation between the various production phases should be maintained. Pigs should be organized together into same-production-phase batches, which should be moved as a group to the pens used for the following phase. All facilities should be thoroughly cleaned and disinfected between batches.
- Vaccination against respiratory pathogens: an appropriate vaccination strategy should be discussed with a qualified veterinarian. This should take into account the epidemiologic situation of your area, and the farm’s history and health goals.
- Feedback from laboratory analysis, post-mortem examinations on farms, and from the abattoir: information from post-mortem examinations, abattoir feedback and results from laboratory analysis can be used as feedback for farmers and herd veterinarians to assess the results of strategies in place to manage pig respiratory health. In this regard, Farm4Trade is developing the ADAL technology and collaborating with Italy’s largest abattoirs, to obtain data on the main respiratory diseases by inspecting carcasses at the slaughterhouse.
Respiratory health is an important issue affecting the swine industry. Farmers must be aware of the factors affecting the respiratory health status of their pigs, and work with herd veterinarians to improve results. This will lead to better pig welfare, and higher levels of profitability for farmers.
- Yaeger MY, Van Alstine WG. (2019) Respiratory system. In Zimmerman JJ, Karriker LA Ramirez A, Schwartz KJ, Stevenson GW, Zhang J. (Eds). Diseases of Swine, 11th Edition Ames, Blackwell Publishing. pp 393 – 407
- USDA (2012) Swine 2012. Part III: Changes in the U.S. Swine Industry, 1995−2012. United States Department of Agriculture, Animal and Plant Health Inspection Service, Veterinary Services, National Animal Health Monitoring System. pp. 41/45.
- Opriessnig T, Giménez-Lirola LG, Halbur PG. (2011) Polymicrobial respiratory disease in pigs. Animal Health Research Reviews, 12(2), p.133.