The inclusion of n-3 long-chain fatty acids in sow and piglet post-weaning diets modifies ileal mucosa immune indicators of low- and high-birth-weight piglets at the end of the post-weaning period

Although n-3 long-chain fatty acids (LCFA) are associated with anti-inflammatory effects, very little is known about their effects on the gut immunity of weaned piglets. The aim of this study was to evaluate the impact of n-3 LCFA in sow and piglet diets on different immune indicators of ileal piglet mucosa 28 d post-weaning. Twelve sows were randomly assigned to a control or an n-3 LCFA diet from insemination until weaning. At birth, the 2 lowest (LBW) and the 2 highest birth weight (HBW) piglets per litter were selected; at weaning, one piglet of each birth weight was randomly assigned to either a control or an n-3 LCFA diet. At the end of the post-weaning period, all piglets were sacrificed and mucosa samples from ileum were collected to determine immune indicators by RT-PCR. An interaction between piglet diet and piglet birth weight was observed for tumor necrosis factor α (TNF-α) (P = 0.022) and toll-like receptor (TLR)2 (P= 0.050). The highest TNF-α concentration was found in HBW piglets fed n-3 LCFA while the lowest was in LBW piglets fed the same diet. However, the highest concentration of TLR-2 was observed in LBW piglets fed the n-3 diet and the lowest in LBW piglets fed the control diet. Moreover, an interaction between maternal diet, piglet diet, and piglet birth weight was detected for interleukin 2 (IL-2) (P = 0.044), interferon γ (INF-γ) (P = 0.037) and TLR-4 (P = 0.001). The highest concentrations of IL-2 and TLR-4 were found in HBW piglets fed the n-3 LCFA maternal and control piglet diet. However, the lowest concentration of IL-2 was observed in HBW piglets fed the control maternal and piglet diet, and the lowest concentrations of TLR-4 in LBW piglets fed the maternal n-3 LCFA and piglet control diet. In terms of INF-γ, the highest concentration was found in LBW piglets fed maternal and piglet control diet, and the lowest in HBW piglets fed maternal and piglet n-3 LCFA diet. To conclude, the inclusion of n-3 LCFA in sow and piglet post-weaning diets modifies gut immunity differently depending on piglet birth weight.

Key Words: swine nutrition, n-3 long-chain fatty acids, gut immunity.

Presented at the 9th Symposium on Gut Health in Production of Food Animals, St. Louis, USA, 2021. For information on the next edition, click here.