Effects of maternal plane of nutrition and increased dietary selenium in first-parity ewes on inflammatory response in the ovine neonatal gut1

Abstract

Many areas of the western United States have soils that have increased Se content, and ruminants grazing these rangelands may ingest increased quantities of Se. In addition, high-energy diets or increased Se intake may induce gut inflammation. The objective of this study was to evaluate the effects of maternal plane of nutrition and increased dietary Se during gestation on inflammatory responses in neonatal lamb ileal tissue, a major immune organ. Rambouillet ewes (age = 240 ± 17 d; initial BW = 52.1 ± 6.2 kg) were allocated to 4 treatments arranged in a 2 × 2 factorial. Factors included Se [adequate Se (ASe, 11.5 µg/kg of BW) or high Se (HSe, 77.0 µg/kg of BW)] initiated at breeding, and nutritional plane [100% (CON) or 140% (HIH) of requirements] initiated at d 40 of gestation. Ewes were fed individually from d 40, and lambs were removed at parturition and fed artificial colostrum and milk replacer. Lambs were necropsied at 20 d of age, and ileal tissues were sampled for immunoblotting and real-time quantitative reverse-transcription PCR analyses. The ASe-HIH and HSe-CON treatments had no effect (P = 0.179) on inflammatory signaling compared with ASe-CON. However, greater inflammatory signaling was detected in the HSe-HIH group, as shown by increased (P < 0.05) mRNA expression of tumor necrosis factor-α and chemotaxis IL-8. Consistently, phosphorylation of c-Jun N-terminal kinase, a primary inflammatory signaling mediator, was greater (P < 0.05) in the HSe-HIH group compared with other treatments. Consistent with cytokine expression, mast cell density was less in the HSe-CON group than in other treatments. The expression of transforming growth factor β mRNA was greater (P < 0.05) in the HSe-HIH group; consistently, collagen content was increased in the HSe-HIH group compared with the ASe-CON group (P < 0.05). In conclusion, independently, neither HSe nor HIH had major effects on inflammation, but in combination, these maternal treatments induced an inflammatory response in the neonatal intestine.