Epidermal Growth Factor Ameliorates Essential Trace Element Absorption in The Gastrointestinal Tract by Regulating The Expression of Microelement Transport-Relative Genes in Lipopolysaccharide Challenged Early Weaning Piglets

Abstract Background: Epidermal growth factor (EGF) plays an important role in nutrient utilization. A 14-days trial was conducted to investigate how EGF attenuates the effect of lipopolysaccharide (LPS) on the growth performance and the nutrient utilization of early-weaned pigs.Methods: A total of 48 early weaned piglets were randomly distributed among 4 groups, which included the control, EGF, LPS and EGF + LPS groups. Each group had 6 replicates and each replicate consisted of 2 piglets. The experiment lasted for 14 d.Results: The results showed that LPS exposure significantly decreased the average daily gain (ADG) and significantly increased the feed conversion ratio (FCR) of the weaned pigs compared with the groups without LPS treatment (P<0.05), while dietary EGF could significantly increase the average daily feed intake (ADFI) compared with the diet without EGF supplementation (P<0.05). The LPS treatment significantly decreased the apparent digestibility of crude fat compared with the groups without LPS treatment (P<0.05). The LPS treatment resulted in a significantly increased concentration of Cu, Fe, Zn and Mn in the stomach, jejunum and ileum chyme, and feces compared with the groups without LPS treatment (P<0.05), while the EGF treatment significantly decreased these indicators compared with the diet without EGF supplementation (P<0.05). In the gastrointestinal tract, the LPS treatment significantly decreased the expression levels of the zrt-irt-like protein 4 (Zip4), zrt-irt-like protein 7 (Zip7), copper transport protein 1 (Ctr1), antioxidant 1 (Atox1), copper chaperone for superoxide dismutase (CCS), cytochrome c oxidase copper chaperone 17 (Cox17), copper-transporting P-type 7A (ATP7A), copper-transporting P-type 7B (ATP7B), divalent metal transporter 1 (DMT1), cytochrome b (CYTB), and transferrin (Tf) genes compared with the groups without LPS treatment (P<0.05), while the EGF treatment significantly increased the expression levels of the Zip4, Ctr1, Atox1, CCS, Cox17, ATP7A, ATP7B, DMT1, CYTB, and hephaestin (Hp) genes compared with the diet without EGF supplementation (P<0.05).Conclusion: Dietary EGF could attenuate the effect of LPS exposure on the essential trace element absorption by changing the expression levels of microelement transport-relative genes of early-weaned pigs.