Abstract Recent studies have indicated that providing an effective probiotic to dams and their progeny allows the pigs to respond more favorably to viral challenges (Lerner et al., 2020; Bertram et al., 2022). Sixteen pregnant dams (parity 1 to 5) allotted by gestation pen were exposed to one of two treatments: Control (CON) where dams consumed a standard, non-probiotic containing, gestation and lactation diet or Bacillus (BAC) where dams consumed standard diets with a daily top dress applied to achieve 1.65 x 106 CFUs of Bacillus/gram of complete feed from 5 weeks before farrowing through lactation. Ninety-six nursery pigs were allotted (48 per treatment group) to the nursery portion of this study at weaning. The CON pigs selected for the nursery received non-probiotic containing feed and BAC pigs selected for the nursery received 1.10 x 106 CFUs Bacillus/gram of complete feed for the 3-wk nursery period of the study. Pigs were separated into 8 pens with 6 pigs per pen by treatment. Individual pig body weights and pen feed intakes were recorded on d 0, 7, 14, and 21. Following 14-d of feed acclimatization post-weaning, all pigs received an H1N2 Influenza viral challenge via intratracheal gavage (Haesebrouck et al., 1986). Clinical signs, including rectal temperatures, respiratory score, abdominal score, and demeanor score we collected daily beginning 1 d before challenge (d 13) through the end of the study. On d 21, following body weight collection, all pigs were euthanized, lungs were removed, and each of seven lung lobes (right and left cranial, right and left middle, accessory, and right and left caudal) were scored on percentage of lobes bearing gross (visible) lung lesions (Halbur et al., 1996). Pigs in the BAC group had better F:G ratios during the pre-challenge (1.177 vs. 1.309, P < 0.01), post-challenge (1.418 vs. 1.633, P < 0.01), and entire growth (1.287 vs. 1.464, P < 0.001) periods, compared with those of the CON group. The percentage of pigs in the BAC group with gross lung lesions in the left and right cranial, accessory, and left and right caudal lung lobes was less than those of the CON group (Table 1). Additionally, total lung lobes with lesions per pig (4.1 vs. 5.3, P < 0.001) were lower in pigs in the BAC group. These data indicate that application of a Bacillus-based probiotic (in this case BioPlus 2B) to sows and subsequently their weaned progeny is associated with better feed efficiency and fewer lung lesions following a challenge with H1N2 Influenza.
Read full abstract