Tail lesions in fattening pigs: relationships with postmortem meat inspection and influence of a tail biting management tool

Abstract

Tail biting is a major welfare and economic problem in intensive pig production. The objectives of this study were to (1) determine tail lesion prevalence at a German abattoir, (2) test for associations between meat inspection findings and tail lesions, (3) assess the agreement between tail necrosis recorded during meat inspection and scored from pictures and (4) test whether the tail biting management tool 'Schwanzbeiß-Interventions-Programm' (SchwIP) had an effect on tail lesion prevalence. A total of three observers scored tail lesions from pictures of 43 328 pigs from 32 farms where SchwIP had been applied, and of 36 626 pigs from 32 control farms. Tail lesions were classified as score 0: no visible lesion, score 1: mild lesion, score 2: severe lesion and score 3: necrosis. In addition, complete loss of tail (CL) was recorded. Tail necrosis was the only tail-related carcase finding recorded by meat inspectors. (1) Tail lesion prevalences in pigs from control farms were 23.6% for score 1, 1.02% for score 2, 0.55% for score 3 and 0.41% for CL. The combined prevalence of any lesion and/or CL was 25.4%. (2) Pleurisy, lung findings, signs of inflammation in the legs, arthritis and abscesses were the most frequent meat inspection findings (prevalences of 8.46%, 8.09%, 2.99%, 0.83% and 0.23%, respectively; n=79 954 pigs). Leg inflammation, arthritis and abscesses were more prevalent in pigs with tail lesions of any degree compared with pigs without tail lesions (3.39% v. 2.83%, 1.06% v. 0.75% and 0.39% v. 0.17%, respectively; all P<0.001, n=79 954 pigs). Pigs with severe tail lesions also had more lung findings (2.00% v. 0.17%, P<0.001). (3) Tail necrosis scored during meat inspection resulted in lower prevalence than scored from pictures (0.22% v. 0.69%; n=79 954 SchwIP and control farm pigs). (4) Although tail lesion prevalence was significantly higher in pigs from SchwIP than in pigs from control farms during the first 3 months (32.2% v. 23.8%, P=0.015), it was not significantly higher during the remainder of the year (22.6 v. 26.9, 24.4 v. 21.4 and 24.0 v. 28.0, second, third and fourth quarters, respectively). In conclusion, meat inspection results in much lower tail lesion prevalences than tail lesion assessment from pictures, even if only the category 'necrosis' is compared. Advising farms on tail biting using the management tool SchwIP helped to decrease the prevalence of tail lesions on problem farms.

Intact Tails as a Welfare Indicator in Finishing Pigs? Scoring of Tail Lesions and Defining Intact Tails in Undocked Pigs at the Abattoir

“…This is further supported by a recent study showing an increasing systemic temperature in pigs with tail lesions of increasing severity (18). Previous studies looking at the link between tail lesion severity and carcass condemnations have mainly included docked pigs [e.g., (5,6,19)]. Valros et al (4) reported an increased risk of condemnations in carcasses with severely bitten tails in a population of mainly non-docked pigs.…”

Multi-Stakeholder Focus Groups on Potential for Meat Inspection Data to Inform Management of Pig Health and Welfare on Farm

“…Whilst MI originally evolved to protect public health, it is now also recognized as an important benchmark of animal health and welfare [37]. Furthermore, pig welfare indicators such as tail and skin lesions reflect on-farm herd health and welfare [7,38], as well as reduced productivity [29,34,36], therefore the inclusion of welfare indicators at MI has an important utility in providing valuable data to inform herd management and health planning. In fact, improved animal welfare can lead to financial benefits for producers and society through reduced mortality, improved health, improved product quality, improved disease resistance and reduced medication, lower risk of zoonoses and foodborne diseases, farmer job satisfaction, contribution to Corporate Social Responsibility, and ability to command higher prices from consumers [39].…”

“…Ideally, feedback to pig producers would include information on economic impact of health and welfare conditions, as well as advice on appropriate management strategies to reduce them, to allow producers to make judgments on cost-effectiveness. The proposed MI tool could therefore be modified to incorporate advice and function as a decision making tool (e.g., see German tail biting risk tool SchwIP [38,55]). The Teagasc eProfit Monitor, which collects technical and financial performance data for Irish pig herds, allows comparison in time and with the top 25% producers [56].…”

“…The use of electronic tags, which would allow identification of individual pigs, and the rapid development in image analysis or machine learning, show promise in improving traceability and could allow automated data recording for pig health and welfare at high line speeds [57,58]. Automated detection of different lesions at MI is a promising new approach in research which is being currently being investigated for a variety of indicators such as lung, heart, liver, skin, ear and tail lesions as well as bursitis [38,[59][60][61]. Ideally, this would allow integration and detailed recording of different indicators including but not limited to carcass condemnations, viscera condemnations, viscera lesions (e.g., lung lesions, gastric ulcers, milk spot), carcass lesions (e.g., tail lesions, skin lesions, loin bruising, ear lesions) or physiological measurements (e.g., blood lactate, creatine kinase, haptoglobin) in future MI systems to provide information on pig health and welfare [6,13,47,58,62,63].…”

Data from routine meat inspection is a poor indicator of the prevalence of tail lesions in undocked pigs

“…Problems on under-reporting of lesions may be resolved by clear instructions on the appearance of normal undocked tails and allowing more time for meat inspection. Vom Brocke et al [9] compared results from meat inspection with an assessment from photos taken at the abattoir. The observed prevalence of tail necrosis (definition not given in the manuscript) was 0.22% when based on meat inspection vs. 0.69% when based on pictures, perhaps indicating, that given more time, a better performance can be obtained.…”