Evaluation of the use of prenatal immune stimulation on the ability to alter postnatal immune function in weaned pigs

Authors: Sanchez, Nicole; MITCHELL, TY - Texas Tech University; Broadway, Paul; BOWEN, BROOKE - Texas Tech University; DAVIS, EMILY - Texas Tech University; DOBBINS, THOMAS - Texas Tech University; BARKER, SAMANTHA - Texas Tech University; LEGAKO, JERRAD - Texas Tech University; PETRY, AMY - Texas Tech University; Carroll, Jeffery - Jeff Carroll

Submitted to: Journal of Animal Science Supplement
Publication Type: Abstract Only
Publication Acceptance Date: 4/17/2023
Publication Date: 11/1/2023
Citation: Sanchez, N.C., Mitchell, T.M., Broadway, P.R., Bowen, B.M., Davis, E.M., Dobbins, T., Barker, S.N., Legako, J.F., Petry, A.L., Carroll, J.A. 2023. Evaluation of the use of prenatal immune stimulation on the ability to alter postnatal immune function in weaned pigs. Journal of Animal Science Supplement.

Interpretive Summary:

Technical Abstract: One of the biggest areas where improvements can be made in swine production is in the area of swine health. This study was designed to determine whether exposure to low dose endotoxin (lipopolysaccharide; LPS) in gestation can enhance immunity to a subsequent challenge in piglets after weaning. Pregnant Camborough sows (parity: 2.6±1.4) were assigned to a prenatal immune stimulation (LPS; n=7; administered 2.5 µg/kg BW LPS i.m. at d 78±1.8 of gestation) or saline treatment group (CON; n=7). From the 2 prenatal treatment groups, barrows (n=17 LPS, 17 CON) were identified at weaning (21±1.3 d of age) to subsequently receive and post-weaning LPS challenge. On d -7, barrows were transported to the USDA-ARS Livestock Issues Research Unit in Lubbock, TX where they were housed in individual pens in an environmentally controlled room with ad libitum access to water and a starter ration. On d -1, pigs were fitted with indwelling jugular catheters and subcutaneous temperature loggers. On d 0, pigs were challenged i.v. with LPS (10 µg/kg BW) and blood samples were collected at -2, 0, 1, 2, 4, 6, 8, 12, and 24h relative to LPS challenge. Data were analyzed using PROC MIXED in SAS, specific for repeated measures. There was a treatment × time interaction for subcutaneous temperature (P<0.01), where temperature increased more quickly at 1 and 2h post-challenge in LPS compared to CON pigs. There was a tendency (P=0.08) for less change in white blood cells, relative to baseline values, in LPS compared to CON pigs. There was a treatment × time interaction (P=0.01) for lymphocyte concentrations where concentrations were reduced in LPS compared to CON pigs at 8h post-challenge. There was also a treatment × time interaction (P=0.01) for the change in eosinophil concentrations, where there was less change in eosinophil concentrations from 1 to 12h in LPS compared to CON pigs. There was a tendency (P=0.08) for a treatment × time interaction for serum interleukin-6 (IL-6), where concentrations were reduced in LPS compared to CON pigs at 2h (P=0.01) and tended to be reduced at 1 and 4h post-challenge (P=0.11). There was a tendency (P=0.06) for a treatment × time interaction for IL-8, where concentrations were reduced in LPS compared to CON pigs at 1 and 4 h (P=0.01) and tended to be reduced at 2 h post-challenge (P=0.06). Granulocyte macrophage colony stimulating factor and tumor necrosis factor-a tended (P=0.08) to be reduced in LPS compared to CON pigs. These data suggest that exposure to endotoxin in utero can influence the postnatal innate immune response to endotoxin. Thus, it is possible to influence the innate immune response of pigs in utero, which may serve as a method to positively influence postnatal immune responsiveness.