Effects of clinoptilolite and modified clinoptilolite on the growth performance, intestinal microflora, and gut parameters of broilers.

The purpose of this study was to evaluate the effect of natural clinoptilolite (NCLI) and modified clinoptilolite (MCLI) on broiler performance, gut morphology, and its relation to gut circumstances. A total of two hundred forty 1-d-old male chicks were randomly assigned to 3 treatments, each of which comprised 8 pens of 10 chicks per pen. Birds in the control group were fed the basal diet, whereas those in the experimental groups were fed diets supplemented with NCLI at 2% (NCLI group) or MCLI at 2% (MCLI group) for 42 d. The results showed that compared with the control, supplementation with NCLI or MCLI had no significant (P > 0.05) effects on productive parameters from d 1 to 42. Supplementation with MCLI and NCLI was associated with greater (P < 0.05) villus height in the jejunal and ileal mucosa compared with those areas in the controls from d 1 to 42. However, supplementation with NCLI and MCLI had no significant (P > 0.05) influence on the crypt depth in the jejunal and ileal mucosa compared with those in the controls. Total viable counts of Escherichia coli were significantly (P < 0.05) decreased by MCLI and NCLI from d 1 to 21. The NCLI and MCLI significantly increased the total viable counts of Lactobacillus acidophilus from d 22 to 42. Small intestine and cecal pH values in the MCLI group were found to be lower (P < 0.05) than those in other groups. Total volatile fatty acid concentrations were significantly (P < 0.05) decreased in both experimental groups from d 22 to 42. This study showed that NCLI or MCLI, as feed additives for broilers, had a positive effect on gut parameters by acting on microbial populations of the digestive tract.