Analysis of cough sounds for diagnosis of respiratory infections in intensive pig farming

Respiratory diseases are widespread causes of mortality and loss of productivity in intensive pig farming. Cough is one of the symptoms and a central element in screening and diagnosis of common illnesses caused, for example, by Pasteurella multocida or Actinobacillus pleuropneumoniae (App). The aim of this research is to compare the acoustic features of cough sounds originating from the mentioned infections and non-infectious cough sounds provoked by inhalation of citric acid by means of labeling and sound analysis. The acoustic parameters investigated are peak frequency and duration of the cough signals. The differences resulting from the sound analysis confirm the variability in acoustical parameters according to health status or disease in the animals. In infections, there is a change in the status of the respiratory system; consequently, infectious coughs are different from non-infectious coughs. The duration of single infectious coughs is considerably different among the types of cough analyzed, which are: non-infectious coughs, App coughs, and P. multocida coughs. Frequency analysis of single coughs allows a more general classification between non-infectious and infectious coughs. Acoustics parameters can be used in an algorithm-based alarm system to automatically identify cough sounds and provide farmers an early warning about the health status of their herds.