Effects of Physical Sizes of Clinoptilolite on Protein Efficiency Ratio, Intestinal Morphology and Growth Indices of Broilers

A total of 448 ross 308 seven-day old male broiler chicks were assigned to seven treatments with four rep-licates, each containing 16 chicks, to determine effects of physical sizes and rate of dietary inclusion of clinoptilolite. the chicks fed diet containing clinoptilolite at 1.5% and particle size of 0.4-0.8 mm showed significantly higher body weight gain than the control group that did not receive clinoptilolite (p < 0.05). adding clinoptilolite to the diet caused a significant improvement in feed conversion ratio during 22-42 and 7-42 days of age (p < 0.05). broilers fed diet containing clinoptilolite at 1.5% and particle size of 0.4-0.8 mm had a lower feed conversion ratio than other groups. addition of clinoptilolite at 1.5% and particle size of 0.4-0.8 mm improved protein efficiency ratio than the control group in periods 22-42 and 7-42 days (p < 0.05). broilers fed diet containing clinoptilolite at 3% and particle size of 0.4-0.8 mm had significantly longer villus height in the duodenum and those fed clinoptilolite at 1.5% and particle size of 0.4-0.8 mm had longer villus height in the jejunum than the control group (p < 0.05). among different dietary treatments, the group receiving 1.5% clinoptilolite and particle size of 0.4-0.8 mm had the greatest ratio of villus height to crypt depth. in conclusion supplementation of diet with clinoptilolite with a particle size of 0.4-0.8 mm had positive effects on performance and intestinal morphology in broilers.