Abstract
Research is needed to validate lesions recorded at meat inspection as indicators of pig welfare on farm. The aims were to determine the influence of mixing pigs on carcass lesions and to establish whether such lesions correlate with pig behaviour and lesions scored on farm. Aggressive and mounting behaviour of pigs in three single sex pens was recorded on Day −5, −2, and −1 relative to slaughter (Day 0). On Day 0 pigs were randomly allocated to 3 treatments (n = 20/group) over 5 replicates: males mixed with females (MF), males mixed with males (MM), and males unmixed (MUM). Aggressive and mounting behaviours were recorded on Day 0 at holding on farm and lairage. Skin/tail lesions were scored according to severity at the farm (Day −1), lairage, and on the carcass (Day 0). Effect of treatment and time on behaviour and lesions were analysed by mixed models. Spearman rank correlations between behaviour and lesion scores and between scores recorded at different stages were determined. In general, MM performed more aggressive behaviour (50.4 ± 10.72) than MUM (20.3 ± 9.55, P < 0.05) and more mounting (30.9 ± 9.99) than MF (11.4 ± 3.76) and MUM (9.8 ± 3.74, P < 0.05). Skin lesion scores increased between farm (Day −1) and lairage (P < 0.001), but this tended to be significant only for MF and MM (P = 0.08). There was no effect of treatment on carcass lesions and no associations were found with fighting/mounting. Mixing entire males prior to slaughter stimulated mounting and aggressive behaviour but did not influence carcass lesion scores. Carcass skin/tail lesions scores were correlated with scores recorded on farm (rskin = 0.21 and rtail = 0.18, P < 0.01) suggesting that information recorded at meat inspection could be used as indicators of pig welfare on farm.
Highlights
Meat inspection is a promising surveillance tool for pig welfare [1,2,3]
There were significantly more aggressive behaviours per hour in mixed with males (MM) than males unmixed (MUM) pigs (P < 0.05), but there were no differences between mixed with females (MF) and MUM pigs on the day of slaughter in general
There was a tendency for MM pigs to have more severe fights than MF pigs at holding, but no differences were found at lairage (Table 5)
Summary
Meat inspection is a promising surveillance tool for pig welfare [1,2,3]. Being animal based, welfare indicators recorded at meat inspection can provide valuable information about conditionsPLOS ONE | DOI:10.1371/journal.pone.0122841 April 1, 2015The Effects of Pre-Slaughter Mixing on Entire Male Pigs on-farm, during transport, at lairage and pre-slaughter handling [3,4,5]. Meat inspection is a promising surveillance tool for pig welfare [1,2,3]. Welfare indicators recorded at meat inspection can provide valuable information about conditions. Research is needed to validate other injuries and lesions recorded on the carcass (i.e. at meat inspection) as welfare indicators. To differentiate skin lesions arising on-farm during different stages of the production cycle from those arising during transport to the abattoir, at lairage or caused by mechanical damage due to abattoir processes [2]. To establish the degree to which lesions recorded on the carcass are correlated to negative behaviours performed by pigs during the production cycle. The relationship between tail lesions scored on the carcass and tail biting behaviour performed by pigs on farm is unknown
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
