Effects of different levels and sizes of clinoptilolite on digestive enzymes activities, tibia bone traits and carcass characteristics of broiler chickens

A total of 448 Ross 308 seven-day old male broiler chickens were randomly distributed in seven treatments of four replicates with 16 chicks/ pen and effects of physical sizes and levels of clinoptilolite were examined. The chicks given clinoptilolite (1.5% with particle size of 0.4- 0.8 mm), showed a significant increase in body weight gain than control group that did not received clinoptilolite during 22-42 and 7-42 days of age (P<0.01). Adding clinoptilolite to the diet caused a significant improvement in feed conversion ratio during 22-42 and 7-42 days of age (P<0.01). Broilers were fed with clinoptilolite (1.5% with particle size of 0.4- 0.8 mm) had lower feed conversion ratio compared to other groups. Broilers were fed with clinoptilolite (1.5% with particle size of 0.4- 0.8 mm) had better protein efficiency ratio compared to control group in periods of 22-42 and 7-42 days of age (P<0.01). The effect of clinoptilolite on digestive enzymes activities (trypsin and chymotrypsin) were significant (P<0.01). So that the activities of trypsin and chymotrypsin were higher in broilers fed clinoptilolite (1.5% with particle size of 0.4- 0.8 mm) than control group. The lowest and the highest amount of tibia ash were obtained in broilers were fed with control and treatment including clinoptilolite (1.5% with particle size of 0.4- 0.8 mm) respectively in day of 42 (P<0.05). Broilers were fed with clinoptilolite (1.5% with particle size of 0.4- 0.8 mm) had higher amount of carcass, breast and gizzard percentage comperd to control group in day of 42. Different treatments hadn’t significant effect on liver, thigh and abdominal percentage (P>0.05). Therefore, it can be concluded that the supplementation of diet with clinoptilolite has positive effects on broilers performance.