Evaluation of the efficacy of Bacillus licheniformis or sodium butyrate in front of a Salmonella Typhimurium oral challenge in piglets

Abstract Text:

The objective of the study was to evaluate the efficacy of Bacillus licheniformis (PROPORC^®; NOREL S.A.) or sodium butyrate (GUSTOR BP70^®; NOREL S.A.) in weanling pigs orally challenged with SalmonellaTyphimurium.

 

72 piglets (28 days old, 8.21±0.79kg) were divided into 24 pens allocated to 3 experimental diets: 1) CTR, base diet without additives; 2) PRO, base diet supplemented with 1 kg/t of PROPORC^® (equivalent to 10⁹ CFU/kg of feed of Bacillus licheniformis); and 3) BUT, base diet supplemented with 3kg/t of GUSTOR BP70^® (containing 70% sodium butyrate protected with vegetable fat). The base diet was multicereal (corn, wheat and barley) with selected protein sources (soybean meal 44, fishmeal and bovine sweet whey), without antibiotics and met NRC 2012 requirements.

 

Consumption and weight gain of the animals were monitored during the trial (16 days). After a week of adaptation, the animals were orally inoculated with Salmonella Typhimurium (1 x 10⁸ CFU). Parameters evaluated after the oral challenge were fecal consistency, rectal temperature (24 and 72 h post-inoculation, PI) and fecal shedding of Salmonella (days 0, 1 and 7 PI). Moreover, on days 4 and 8 PI one animal in each pen was euthanized to evaluate the serological inflammatory response (TNFα and Pig-Map), the microscopic ileal morphology, and the presence of Salmonella in the colon.

No significant differences between treatments were seen on performance, fecal consistency, rectal temperature or inflammatory markers (P>0.05). However, a trend to reduction was observed in Salmonella prevalence in feces on day 7 PI (100, 75 and 75, P=0.074) and significant reduction in colon on day 8 PI (88, 50 and 63, P=0.043), for CTR, PRO and BUT respectively. Besides, on day 4 PI crypt depth showed a tendency to increase with the two supplemented diets (203, 239 and 251 203 μm, SEM±15.9, P=0.107), for CTR, PRO and BUT respectively.

The results obtained demonstrate that the administration of Bacillus licheniformis (10⁹ CFU/kg) or sodium butyrate (3kg/mT) could improve intestinal morphology and reduce the colonization and fecal shedding of SalmonellaTyphimurium in piglets.

Keywords: Salmonella, probiotic, sodium butyrate