Control of the respiratory diseases in a pig herd using data of the respiratory organs examination of fattening pigs at a slaughterhouse

In everyday farming practice, assessment of economical impact of respiratory diseases at herd level relies on the following information: data records on the diseases within the herd, productivity and slaughterhouse records. The data available from the slaughterhouse encompass the number and percentage of low weight pigs, number of diseased animals, the severity of lesions observed at slaughter as well as the amount of discarded organs and carcasses. The aim of this investigation is to improve the assessment of health status of pigs at herd level and design programs for the control of respiratory syndrome in swine based on the analysis of the data collected at slaughter line. In the slaughterhouse, the thoracic cavity organs from 105 fatlings that have reached the slaughter body mass, 20 underweight fatlings and 20 underdeveloped piglets were examined. The weight of both half-carcasses was measured. Tissue samples of altered organs (lungs, mediastinal lympho nodes, tonsils) were collected and subjected to bacteriological analysis. The average weight of both half-carcasses was 81.54kg in fatteners with full slaughter body mass, and 58.29kg and 14.95kg in lowweight fatlings and piglets, respectively. Changes affecting 10% of lung tissue were established in 9 animals, 11-20% in 10 and 21-32% in 10 fatlings. Pathological process is characterized by hepatization of lung tissue, inflammation of the pleura or, even more frequently, adhesions between the visceral and parietal pleura and pericardium. In underweight fatlings, the rates of lung changes were ?20% in 5, 11-30% in 3, ?40% in 4, and ?40% in 6 animals. Applying bacteriological testing, the following microorganisms were isolated: Haemophilus parasuis, Arcanobacterium pyogenes, and Pasteurella multocida. The examination performed at the slaughter line strongly suggested the necessity of designing a new, updated vaccination program taking into consideration the causative agents and vaccination schedule.