Zinc-loaded aluminosilicate minerals improve growth performance and alleviate inflammatory response in broiler chickens challenged with avian pathogenic Escherichia coli.

Abstract

This study was conducted to evaluate the protective effects of zinc-loaded aluminosilicate minerals, zinc-loaded zeolite (Zn-ZEO) and zinc-loaded montmorillonite (Zn-MMT), on avian pathogenic Escherichia coli (APEC)-challenged broilers. A total of two hundred and forty one-day-old male Arbor Acres broiler chicks were divided into four groups with six replicates of ten birds each for a 21-day trial. The control and the APEC challenge groups were fed a basal diet, while the Zn-ZEO and Zn-MMT groups received the basal diet supplemented with 1000 mg/kg of Zn-ZEO or Zn-MMT, respectively. At 14 days, birds in the APEC and zinc-loaded aluminosilicate mineral groups were inoculated with APEC suspension. Both zinc-loaded aluminosilicate minerals restored weight gain and feed efficiency in APEC-infected birds (P < 0.05). Zn-ZEO and Zn-MMT inhibited Escherichia coli colonization in the cecum and its translocation to the liver and spleen, with Zn-MMT additionally reducing cardiac Escherichia coli translocation (P < 0.05). The two zinc-loaded aluminosilicate minerals normalized serum &#x3b1;1-acid glycoprotein and triglyceride levels in APEC-challenged chickens (P < 0.05). Zn-MMT further reduced serum adrenocorticotropic hormone and C-reactive protein levels while restoring serum glucose and total cholesterol levels (P < 0.05). Zn-MMT or Zn-ZEO restored cytokine concentrations in serum, spleen, and intestinal mucosa in APEC-challenged chickens (serum interferon-&#x3b3;, splenic interleukin-10, jejunal interleukin-1&#x3b2; and interferon-&#x3b3;, and ileal interleukin-4) (P < 0.05). Furthermore, Zn-MMT normalized a broader range of cytokines in serum (interleukin-6, interleukin-4, interleukin-10, and tumor necrosis factor-&#x3b1;), spleen (interferon-&#x3b3; and interleukin-4), and intestinal mucosa (jejunal tumor necrosis factor-&#x3b1; and interleukin-4, and ileal interferon-&#x3b3;, tumor necrosis factor-&#x3b1; and interleukin-10) through the inactivation toll-like receptor 4 signaling (P < 0.05). The zinc-loaded aluminosilicate minerals restored immunoglobulins in serum, jejunal mucosa, and/or ileal mucosa (immunoglobulin A, secretory immunoglobulin A, and/or immunoglobulin M), with Zn-MMT normalizing a wider spectrum of immunoglobulins (P < 0.05). These findings demonstrate that Zn-ZEO and Zn-MMT both effectively improved growth performance and alleviated inflammation in APEC-challenged broilers, with Zn-MMT exhibiting more pronounced effects.