Abstract: 【Objective】This study aimed to make a comparative analysis of salivary cortisol level before and after transport, behavior during lairage, blood welfare indicators at slaughter of pigs housed in two rearing environments. Carcass traits and meat quality also were evaluated. 【Method】A total of 144 DLY pigs (half of castrated male and female) with body weight (BW) of 27.08±1.06 kg were randomly assigned into either the concrete floor house (CFH) treatment or the deep litter house (DLH) treatment. Each treatment had 6 pens (6 replicates), and according to the similar rearing density (0.85m²/animal), each replicate for CFH and DLH had 10 and 14 pigs, respectively. Animals had always access to feed and fresh water. Feed intake was recorded during the experimental period, and pigs were weighed individually on day 64 and 106 to get the growth performance. At the end of experiment, 10 pigs (half of castrated male and female) with approximately BW of 105 kg from each treatment were selected for slaughter. Salivary samples were collected at home pens (-60 min), 0 and 120 min during lairage for the cortisol analysis, and behavior video during lairage was recorded for observation of pigs’ behavior. Blood samples at slaughter were collected for the analysis of the plasma level of glucose, lactate, cortisol and creatine kinase (CK). Carcass traits (carcass percentage, carcass drip loss, backfat depth and muscle depth) and meat quality (pH value, meat color, intramuscular fat and drip loss) in Longissimus dorsi (LD) were evaluated. 【Result】 Final body weight, average daily feed intake, average daily gain, and feed/gain ratio of pigs from CFH did not show difference from those of pigs from CFH (P＞0.10). DLH pigs had higher salivary cortisol level in the home pen, and 0 and 120 min at lairage after transport than CFH pigs, but salivary cortisol rise at 0 and 120min lairage in DLH pigs as compared with the home pen measurement was lower than in CFH pigs (0 min, + 2.85±0.66 vs. + 5.08±1.33, P＜0.01; 120 min, + 1.03±0.63 vs. + 2.66±1.54, P=0.04). There were no differences in pigs spending time in resting, standing, exploring, walking, fighting and drinking between DLH and CFH during 0-60 min at lairage (P＞0.10). During 60-90 min, however, CFH pigs spent more time in exploring, walking and fighting compared with DLH pigs (P＜0.05). Compared with CFH pigs, DLH pigs at slaughter had similar plasma glucose level (P＞0.10), but lower levels of lactate and CK, and a higher tendency for cortisol level (P=0.07). Carcass percentage, carcass drip loss, backfat depth and muscle depth from DLH pigs did not show difference from those of from CFH pigs (P＞0.10). Concerning the meat quality, DLH tended to have more intramuscular fat content and less drip loss in LD (P=0.10), whereas pH_45min, pH_24h and meat color (L*, a* and b*) were unaffected (P＞0.10).【Conclusion】DLH could decrease time spent in fighting behavior during lairage and physiological response to pre-slaughter handling in pigs. These data showed DLH could improve the ability to copy with pre-slaughter stress in pigs. However, DLH had no effects on growth performance, carcass traits and meat quality.

Key words: rearing environment, pig, pre-slaughter behavior, salivary cortisol, carcass strait, meat quality