Implications of coping characteristics and social status for welfare and production of paired growing gilts

Abstract

This paper considers the question whether knowledge on individual coping characteristics of growing pigs may be used to improve welfare and production after mixing. Gilts with either reactive or proactive coping characteristics were identified according to behavioural resistance in a backtest, respectively, being low (LR) and high resistant (HR) in this test. At 7 weeks of age, several pairs of unfamiliar gilts were formed, and pairs and dominance relationships were studied over a 3-week period. The following pairs (combinations) were established: two LR gilts (LR/LR; n ¼ 12), two HR gilts (HR/HR; n ¼ 12), one LR and one HR gilt (LR gilt dominant: LR(d)/HR; n ¼ 11), and one LR and one HR gilt (HR gilt dominant: LR/HR(d); n ¼ 12). Results showed that on the day of mixing, aggression subsided less quickly and increases in body temperature were higher in LR/ HR(d) and HR/HR pairs. Also, during the first week post-mixing, feed efficiency was lower and skin damage was higher in LR/HR(d) and HR/HR pairs. Mixing of two HR gilts caused highest levels of stress, indicated by greater catecholamine concentrations in urine following the day of mixing, and higher baseline levels of plasma ACTH at 1 week post-mixing. The lower tendency of gilts within HR/HR pairs to contact a novel object may present higher fearfulness. In contrast to those of LR/HR(d) pairs, responses of LR(d)/HR pairs revealed much lower levels of stress, which emphasised the importance of dominance relationships, being independent of coping characteristics of individual gilts. We speculate that in LR/HR pairs, dominant LR gilts were able to suppress aggressiveness of HR subordinates. HR or proactive gilts, however, may become aggressive when being dominant. General effects of social status, independent of combination, were also found. Compared to dominants, subordinates showed higher acute cortisol, body temperature and vocal responses to mixing. In the longer term, they showed a higher vocal and parasympathetic responsitivity towards the novel object, and their body growth was impaired. Measures not influenced by combination and social status included those of leucocyte subsets, prolactin, and average heart rates during novelty tests. To conclude, aggressive conditions in newly formed groups, and consequently welfare and production, may largely depend on coping characteristics of individual pigs, but also on dominance relationships. Accordingly, the practical value of the backtest is being discussed. #

Effects of scalding and dehairing of pig carcasses at abattoirs on the visibility of welfare-related lesions

“…The association between welfare-related carcass lesion frequency and average CCW is unsurprising; previous Visibility of welfare lesions in slaughter pigs research has found that skin and tail lesions are associated with reduced feed intake and growth due to the effects of infection and stress (Wallgren and Lindahl, 1996;Ruis et al, 2002;Marques et al, 2012). Lower carcass weights are a source of indirect financial loss to producers (Harley et al, 2014).…”

The use of pigs in neuroscience: Modeling brain disorders

“…Attempts have been made to categorize individual pigs within a test group according to certain coping styles reflecting individual adaptive patterns of behavior and physiology to the surrounding environment (Bolhuis et al, 2003(Bolhuis et al, , 2005aD'Eath and Burn, 2002;Forkman et al, 1995;Hessing et al, 1993;Janczak et al, 2003;Ruis et al, 2000Ruis et al, , 2002van der Kooij et al, , 2003. In most of these studies, the possible characterization of pigs was according to their inclinations to respond either actively (proactive) or passively (reactive) to different situations, which is a well-known phenomenon in many animal species (for review, Koolhaas et al, 1999).…”

Coping Style Modifies General and Affective Autonomic Reactions of Domestic Pigs in Different Behavioral Contexts

“…Studies in rodents basically distinguish between proactive and reactive coping (Koolhaas et al, 1986 [rats]; van Oortmerssen et al, 1985 [mice]) and studies in fish and birds often use the terms shyness and boldness (Wilson et al, 1994). In pigs, the concept of coping is also supported, although the extremes in the population do not represent distinct categories of pigs (Ruis et al, 2002; Zebunke et al, 2015). Studies focusing on coping styles in animals suggest that the proactive response is characterized by a typical active fight-flight response in aversive situations which is associated with territorial control, aggression and risk-taking (Cannon, 1929; Benus et al, 1990; Mount and Seabrook, 1993; Koolhaas et al, 1999).…”