Effects of dietary chromium propionate on growth performance, intestinal barrier function, and intestinal immune response in broilers.

This study was conducted to investigate the effects of chromium (Cr3+), provided as chromium propionate (CrProp), on intestinal health, digestion and immune response in broilers under normal rearing conditions. One-day-old broiler chicks (n = 192) were assigned to either a control group, offered a basal diet, or a CrProp group, in which the birds were fed the basal diet supplemented with Cr3+ at 0.2 mg/kg. The results showed that CrProp did not affect ADG and FCR (P > 0.05), but significantly increased ADFI during 22 to 42 days of age (P = 0.05). However, compared with the control, CrProp supplementation increased serum BUN and TG concentrations on day 42 (P < 0.05). Furthermore, CrProp supplementation significantly increased jejunal amylase activity on both day 21 and day 42 and trypsin and lipase activities on day 21 (P < 0.05). CrProp treatment also enhanced lipase activity in the duodenum and jejunum on day 42 (P < 0.05). On day 21, the mRNA expression levels of IL-10, TNF-α, IFN-γ, MUC2, claudin-1, occludin, and ZO-1 were significantly upregulated in the CrProp group compared to those in the control group in both the duodenum and jejunum (P < 0.05). On day 42, the expression of IL-10 and MUC2 was notably elevated in the CrProp group (P < 0.05). Overall, our findings indicated that dietary CrProp supplementation heightened immunity, increased digestive enzyme activity, and improved intestinal barrier integrity in broilers, suggesting its potential as a beneficial feed additive for gut health.