An abattoir investigation into the Tail Biting Syndrome in pig carcases from selected problem herds

Abstract :

Tail biting in pigs is an abnormal behavioural pattern causing tail necrosis and is frequently associated with local abscess formation. The range of lesions found at post mortem inspection can include visceral and spinal abscesses and haemorrhagic infarcts, particularly in the lungs: collectively diagnosed as pyaemia. The combination of these clinical and post mortem signs resulting from tail biting, with the tail in varying stages of necrosis, is known as the tail biting syndrome. It is the most important and most frequent form of cannibalism in pigs, can be of great economic importance and is a sign of impaired well-being amongst intensively housed pigs. Economic implications of the tail biting syndrome are experienced at the feed conversion efficiency and growth rate level (the animal health significance) and due to the loss at post slaughter inspection (the meat marketing significance). From March to June 1992, 10 111 freshly slaughtered pig carcasses from seven selected pig producer herds were examined at a selected abattoir. Penny’s 1981 classification of bitten tails was used to evaluate the degree of tail necrosis. The economic loss due to the tail biting syndrome was analysed retrospectively based on the recorded price per kg of each carcass during the investigation. The overall figure for the tail biting syndrome was 2,08% and there was a marked sex prevalence. In castrated males the figure was 3,41% and in the entire males 2,05%, whereas in females it was only 1,30%. There was also a significant difference between market mass groupings, the prevalence in porkers being 1,68% and 2,49% in baconers. The prevalence of mild tail .necrosis was significantly higher than that of moderate and severe cases and entire male pigs and porkers showed overall a more severe tail necrosis. There was a relationship between the degree of tail necrosis and lesions occurring in other locations. Those pigs with a severe tail necrosis had a significantly higher prevalence of other location involvement (p = 0,000 < 0,05). Tail biting was the main reason for carcass condemnation due to pyaemia, 94,44% being due to this syndrome. In this investigation, 38,64% of total carcass condemnations, or 54,84% when process faults were excluded, were due to the tail biting syndrome. It was found to be the most important reason. The producers' loss due to carcass condemnation was R11 241 and of this, R4 583 or 40,77% was due to the tail biting syndrome. Partial carcass condemnation and down classification did not significantly influence the price paid to the producer in this survey. No assessment of the extent of this syndrome was possible between docked and undocked pigs because all the pigs sampled had docked tails. The aetiological agents should be identified, the significance of this syndrome to pig animal health should be investigated and the monitoring of this syndrome as an indication of animal welfare status and well-being should be standardized further.   Details

Author Lee HW
URL http://hdl.handle.net/20.500.11892/173506
Date Accessioned 2016-09-26T06:26:16Z
Date Available 2016-09-26T06:26:16Z
Date Created
Identifier URL 1993
Language English
Subject Veterinary science
Subject 2 Veterinary science
Alternative Title DPhil (Argeologie)
Degree Type Masters degree
Degree Description  M MedVet