Effects of Dietary Zeolite Supplementation as an Antibiotic Alternative on Growth Performance, Intestinal Integrity, and Cecal Antibiotic Resistance Genes Abundances of Broilers

Simple Summary: The widespread use of antibiotics in livestock production has attracted public attention due to antibiotic resistance. It is necessary to search for antibiotic alternatives in feeds. Zeolite, a kind of feed additive or feed raw material, can enhance growth performance, balance intestinal bacteria, and improve antioxidant capacity in animals. In vitro studies showed zeolite could reduce antibiotic resistance genes (ARGs) abundances. This research compared the effects of antibiotics and zeolite on growth performance, intestinal morphology and barrier function, and cecal ARGs abundances of broilers. Our results indicated that dietary zeolite supplementation exerted similar or better effects than antibiotic inclusion. Abstract: The study investigated the effects of dietary zeolite supplementation as an antibiotic alternative on growth performance, intestinal integrity, and cecal antibiotic resistance genes abundances of broilers. One-day-old chicks were assigned into three groups and fed a basal diet or a basal diet supplemented with antibiotics (50 mg/kg) or zeolite (10 g/kg). Antibiotic or zeolite increased (p < 0.05) average daily gain (ADG) from 1 to 42 days and duodenal villus height to crypt depth ratio (VH:CD) at 21 days. Zeolite increased (p < 0.05) ADG and average daily feed intake from 1 to 21 days, jejunal VH:CD at 21 and 42 days, ileal VH and VH:CD at 42 days, zonula occludens-1 mRNA abundance at 21 days, and duodenal occludin mRNA abundance at 42 days, whereas reduced (p < 0.05) jejunal CD and malondialdehyde levels in ileum at 21 days and duodenum at 42 days, serum D-lactic acid and diamine oxidase levels at 42 days, and plasma lipopolysaccharide content at 21 and 42 days. Antibiotics reduced (p < 0.05) duodenal claudin-2 mRNA abundance at 21 days, whereas increased (p < 0.05) cecal tetB abundance at 42 days. These findings suggested that the beneficial effects of zeolite in broilers were more pronounced than that of antibiotics.