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The 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. |
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