Relationships between behavioral and meat quality characteristics of pigs raised under barren and enriched housing conditions.

Abstract

In this study the effects of barren vs enriched housing conditions of pigs on their behavior during the lairage period (2-h holding period before slaughter), carcass characteristics, postmortem muscle metabolism, and meat quality were studied. The barren housing system was defined by common intensive housing conditions (i.e., with slatted floors and recommended space allowances), whereas the enriched environment incorporated extra space and straw for manipulation. Salivary cortisol concentrations were measured before transport and at the end of the lairage period. During the lairage period the percentage of time spent walking and fighting by the pigs was registered. Carcass characteristics such as weight, meat percentage, and backfat thickness were determined. At 5 min, 45 min, 4 h, and 24 h postmortem, pH, temperature, and lactate concentrations were determined in the longissimus lumborum (LL) and biceps femoris (BF) muscles. Capillarization of the muscle, mean muscle fiber area, and color and drip loss after 2 and 5 d of storage were determined for both muscle types. Pigs from the barren environment had a significantly higher increase in cortisol from farm to slaughter, but no differences in behavior were observed during the lairage period. Carcass characteristics did not differ between pigs from barren and those from enriched housing conditions. Postmortem lactate formation was significantly lower in LL muscles of enriched pigs at 4 and 24 h postmortem. Capillary density and mean muscle fiber area did not differ between the groups of pigs. The percentage of drip loss at 2 and 5 d after storage of LL muscle samples from enriched-housed pigs was significantly lower than that of the barren-housed pigs. Similar tendencies were found for the BF muscle from pigs kept in an enriched environment, but these were not statistically significant. The housing system did not affect meat color. It is concluded that on-farm improvement of animal welfare by environmental enrichment can also lead to beneficial economic effects after slaughter by improving the water-holding capacity of pork.

Influence of production system in local and conventional pig breeds on stress indicators at slaughter, muscle and meat traits and pork eating quality

“…Thus, the A system did not modify the behaviour and physiological responses of either LW or B pigs to the preslaughtering procedure, which is in accordance with previous results on A v. C system comparisons (Lebret et al, 2006 and. Other studies also showed no effect of enriched environment (increased space allowance, straw bedding) on physiological stress indicators assessed at the end of the lairage period, although the housing conditions influenced animal activity during transport (Geverink et al, 1999;Klont et al, 2001). Conversely, Foury et al (2011) Lebret, Ecolan, Bonhomme, Méteau and Prunier skin lesions and lower plasma CK at slaughter in pigs housed on sawdust bedding with outdoor access compared with conventional housing; however, in their study, pigs were slaughtered in an industrial slaughterhouse, generating more stressful conditions as demonstrated by the much higher average levels of skin lesions and plasma CK levels compared with the present study.…”

“…B pigs also had lower GP due to lower concentrations of all GP components (P < 0.015), reduced total water loss due to lower drip, thawing and cooking losses (P < 0.001), as well as lower breaking energy and shear force of cooked meat (P < 0.001). These results are consistent with the well-known positive relationships between pH1 and pHu values, redness and mechanical tenderness of pork, whereas lightness and water loss are negatively related to pH1 and pHu as well as GP to pHu (Monin, 1988;Warriss, 2000;Klont et al, 2001). These breed differences can be interpreted as higher sensory quality of meat from B pigs and confirm the results obtained on the LM of B compared with LW pigs by Alfonso et al (2005) for pH1, pHu, lightness and redness and by Labroue et al (2000) for pHu, lightness, redness and water-holding capacity.…”

“…As mentioned above, the decreased lightness and water loss and increased dark red colour of BE pork agree with their higher pH1 and pHu values, respectively (Monin, 1988;Klont et al, 2001;Lebret et al, 2006). The marked effect of the production system on meat colour (h°) could also be partly explained by the older age of the BE pigs, as increased myoglobin content has been found in the muscles of Iberian pigs between 350 and 420 days of age (Mayoral et al, 1999).…”

Effects of deep-bedded finishing system on market pig performance, composition and pork quality

“…reduced excitability in hogs, which in turn allowed easier handling and less stress prior to slaughter. One of the hypotheses of the current study was that deep-bedded semi-outdoor finishing environments may reduce stress susceptibility and behaviours that have been noted to lead to aberrant pork quality (Sather et al, 1997;Klont et al, 2001). In the current experiment, the effect of finishing environment had minor influence on pork quality attributes, with the main difference between the two finishing treatments being an increase in marbling within the loin in CON-finished pigs.…”

“…In addition, using deep-bedded structures is an environmental enrichment strategy that has been shown to stimulate foraging and/or explorative behaviour (De Jong et al, 1998;O'Connell et al, 2004). Housing pigs in alternative environments also supports increasing spontaneous exercise and exploratory behaviour (BartonGade and Blaagjerg, 1989;Gentry et al, 2002b;Morrison et al, 2003a), which may lead to changes in stress susceptibility, thereby influencing growth performance and ultimate pork quality (Klont et al, 2001;Morrison et al, 2003b). Few studies have compared growth characteristics from confinement systems to deep-bedded systems (Gentry et al, 2002a;Honeyman and Harmon, 2003).…”