Behavior of pigs infected with Salmonella and fed diets containing a probiotic or a physiological promoter

Abstract Text:

This trial evaluated the effects of a Bacillus licheniformis (10⁹ CFU/kg of feed; PROPORC; NOREL S.A.) and a physiological promoter based on sodium butyrate (3 kg/t feed; GUSTOR BP70; NOREL S.A.) on the behavior of pigs challenged with Salmonella Typhimurium. A total of 72 piglets, weaned at 28 d, were housed in 24 pens and fed 3 diets: 1) Control diet (CTR), 2) CTR + probiotic (PRO), and 3) CTR + physiological promoter (PHP). After a 1-week adaptation period, pigs were orally challenged with 10⁸ CFU of SalmonellaThyphimurium. Behaviors were recorded in the morning and afternoon (8:30 to 10:30 h and 14:00 to 16:00 h) for 5 d beginning 2 d before of the challenge (day -2 and -1) and 3 d after the challenge day (day 2, 3, and 4 post infection, PI). Use of the space (feeder, light, drinker areas), active behaviors (exploration, feeding, drinking, walking and others) and inactive behaviors (lying ventrally or laterally, and in contact or not with a pen mate) were registered. A repeated measures procedure was used for statistical analysis. No effect of PHP was found. Effects of PRO were observed mostly during the morning: Active behaviors as well as inactive behaviors were higher and lower in pigs fed PRO (P<0.008 and P<0.001, respectively) compared with the other groups. These animals spent less time lying in contact with pen mates (P=0.012) while total time exploring the pen, feeding and other active behaviors, were higher (P=0.05, P=0.003 and P=0.03, respectively). In contrast, the total time lying laterally and ventrally with contact was significantly lower on pigs fed PRO (P<0.001 and P=0.008 compared to CTR and PHP respectively).Pigs fed the PRO used more the feeding area (P=0.02) and less the lying area (P<0.001).  In the afternoon pigs were more active before the challenge than on day 4 PI (P<0.001). Before inoculation there were significantly less pigs lying ventrally in comparison with the day 2 and 4 PI (P=0.01). Positive contacts, exploration and feeding behaviors were also less frequent on day 4 PI in comparison with the day before challenge (P<0.05). The use of feeder area decreased (P=0.001) after the challenge. In conclusion the PRO has a positive effect on some behavioral measures, mainly those related to the exploring the pen, feeding and other active behaviours in the morning.

Keywords: probiotics, Salmonella, sodium butyrate