Abstract: This investigation was carried out to study the effect of glutamine supplementation on the jejunum morphological structure of broiler chickens. 288 1-day-old AA chicken were used in a completely randomized experiment with three treatments and three repetitions per treatment, Group Ⅱ and group Ⅲ, respectively, being supplemented with 0.4% and 0.8% glutamine and group Ⅰ, the control, not supplemented. Jejunum samples were taken at 1, 2, 3, 4 weeks of age for morphological studies under light microscope. The results showed, there were different effect of glutamine supplementation on villus height, villus width, crypt depth, muscle layer of mucous membrane thickness, muscle layer thickness and serous membrane layer thickness during all the experimental weeks of age. It was demonstrated that 0.4% and 0.8% glutamine supplementation significantly increased the villus height during all experimental weeks of age and the muscle layer of mucous membrane thickness at one and two weeks of age (P<0.05 or P<0.01), as well as increased the muscle layer thickness and the serous membrane layer thickness (P>0.05); However, glutamine decreased the villus width and the crypt depth (P>0.05).

Key words: glutamine, broiler, jejunum, villus, morphological structure