Supplementation with quaternary benzo(c)phenanthridine alkaloids decreased salivary cortisol and salmonella shedding in pigs after transportation to the slaughterhouse

FOODBORNE PATHOGENS AND DISEASE, Volume 12, Number 11, 2015The present study was aimed at evaluating the effect of herbal extracts supplementation, particularly quaternary-benzo(c)phenanthridine alkaloids (QBA), which have been previously demonstrated to have anti- inflammatory, antimicrobial, and immune-modulator effects. We investigated the role of QBA on stress re- sponse and Salmonella shedding in finishing pigs transported to the slaughterhouse. A total of 82 pigs were orally challenged with a Salmonella cocktail (day 0) containing Salmonella Meleagridis, Hartford, Bo- vismorbificans and Newport serovars and randomly assigned to three treatment groups after 2 wks (day [D] 14): T1, in-feed QBA; T2, in-feed and water-soluble QBA; CON, nonsupplemented). Pigs were transported to the slaughterhouse 2 weeks after intervention (D 28) and slaughtered after nearly 19 h (D 29). Saliva, fecal samples, and carcass swabs were collected from all pigs. Salivary cortisol, Salmonella shedding, and carcass contami- nation were measured. A high positive correlation (Spearman rank correlation coefficient range 0.82–0.93) between salivary cortisol and Salmonella shedding was found after transportation in all groups ( p < 0.05). Only the CON group showed an increase in salivary cortisol after transportation (5.48 ng/mL; p < 0.0001) to con- centrations that were higher than in T1 (2.73 ng/mL; p = 0.0002) and T2 (1.88 ng/mL; p < 0.0001). Salmonella prevalence and shedding decreased after transportation in pigs receiving the QBA intervention ( p < 0.05), whereas the control group showed a significant increase in Salmonella shedding after transportation ( p = 0.04). At D 28, pigs in T2 shed lower numbers of Salmonella as compared to T1 (1.3E + 02 CFU/mL versus 8E + 03 CFU/mL; p = 0.002). Additionally, carcass contamination by Salmonella was higher in the CON group than the treated groups ( p = 0.01). The findings show QBA intervention was effective in reducing transportation stress of pigs, resulting in reduced Salmonella shedding and positively impacting animal welfare and pork safety