الملخص

   This investigation at hand was conducted to evaluate histological changes of proventriculus and spleen of broiler that fed a vegetable diet contains 10% guar (Cyamopsis tetragonoloba) meal powder. 60 birds (Ross 308 strain) used were assigned into two groups with thirty chicks, fed on vegetable diet contain protein, the first group fed on diet contain 0% of guar meal powder as a control group (G1), and the second group (G2) fed diet contain 10% of guar meal till the end of the experiment, so the current study revealed that the guar meal was effective on digestion process in proventriculus led to histological effective on the proventriculus which a statistically significant increase P≤0.05 was observed in the diameter of proventricular glands, along with a similar significant increase P≤0.05 in diameter of the lumen of the proventricular glands, while there was no significant difference in the diameter of white pulp of the spleen.