Effects of dietary probiotics and their combination with copper-loaded montmorillonite on growth performance,...

This experiment was conducted to investigate the effects of dietary compound probiotics and their combination with copper-loaded montmorillonite (Cu-MMT) on growth performance, intestinal digestive function and nitrogen metabolism in yellow-feathered broilers. A total of 720 1-day-old male broilers were randomly assigned to 3 groups with 6 replicates per group and 40 birds each. The control group (CON group) was fed with a corn-soybean meal basal diet, the probiotic group (P group) was supplemented with 500 mg/kg compound probiotics in the basal diet, and the combined group (PM group) was further supplemented with 1000 mg/kg Cu-MMT in the diet of P group. The experiment lasted for 60 days. The results showed that both treatment groups, particularly PM group, significantly reduced the feed-to-gain ratio (F/G) compared with the CON group in the late growth stage (22 to 60 d) and the whole growth period (P < 0.05). Moreover, PM group showed enhanced the apparent metabolizability of crude ash, both P and PM groups promoted the development of intestinal villi morphology, increased duodenal trypsin and lipase activities, and simultaneously inhibited the activity of serum xanthine oxidase (XOD), thereby reducing the contents of urea nitrogen (UN) and ammonium nitrogen (NH₄⁺-N) in feces. Additionally, PM group significantly decreased fecal pH value (P < 0.05) compared to the CON group and P group. These results indicated that probiotics and their combination with Cu-MMT can reduce F/G, improve intestinal digestive function, and regulate nitrogen metabolism in yellow-feathered broilers.