Enfoque novedoso para el seguimiento de las enfermedades respiratorias en cerdos de engorde

Introduction

Algorithms have been developed to detect cough in pigs and recently the automated tool “Pig Cough Monitor” became available. Real time sound analysis to detect cough in pigs has been showing promising results when used experimentally and based on these laboratory trials, it could be demonstrated that cough in pigs could be identified correctly in 94% (1). Pen- based oral fluid sampling has proven to be an efficient method for surveillance of infectious diseases in swine populations. The purpose of the trials were to monitor respiratory diseases in three subsequent batches of fattening pigs by means of the Pig Cough Monitor and to possibly link cough to pathogen exposure.

Materials and Methods

The trial was carried out in 3 consecutive batches of fattening pigs in a commercial herd in North-West Germany in 2012 and 2013. One batch consisted of approximately 100 pigs, which was placed in one room with 4 pens with 25 pigs each. Each pen was equipped with one microphone transmitting continuous sound signals for 4 months to the Pig Cough Monitor, resulting in 4 microphones per room. The herd had a history of circulating PRRSV, SIV and Mycoplasma hyopneumoniae (Mh). Monthly serum samples of 2 animals per pen were obtained for all 3 batches and pen-based oral fluid samplings were obtained each week for the last batch and all samples were analyzed for presence of antibodies against PRRSV, SIV as well Mh in order to possibly link the presence of “cough” to infection with either pathogen.

Results

In all batches a daily cough pattern approximately 20 coughs/pen/hour could be observed irrespective of any exposure to respiratory pathogens. All batches were exposed to SIV in the middle and PRRSV at the end of the fattening period. Infection of with SIV resulted in a paroxysmal increase of coughing in all batches. The first batch of pigs was exposed to infection with Mh approximately at 17 weeks of age, which was followed by a distinct increase in cough. The second batch of pigs was not exposed to Mh and had no distinct increase in the pattern of cough. Infection with SIV and PRRSV alone did not result in an increase of cough in the second batch, whereas a subsequent PRRSV infection of infection with Mh seems to result in a further increase in coughing in the first batch. Pen-based oral samplings allowed a timely and animal friendly surveillance of herd health in the third batch.

Graph 1: Course of cough of the 3 batches

Conclusions and Discussion

The continuous monitoring of cough by means of the Pig Cough Monitor in a German fattening herd enabled an objective measurement of “respiratory health” or cough respectively. Further studies are needed to analyze the possibility to discriminate the different types of cough.

References

1. A.Van Hirtum and Berckmans D.; Medical engineering & physics 24: 541-545 (2003)