author(s)
Manju G Preedaa, P Selvaraj, P Visha, K Balasundaram, MR Purushothaman and N Murali

abstract
The present investigation was carried out to study the effect of supplemental tryptophan on oviductal histomorphological structures of white Leghorn layers. A total of 350 White Leghorn layers of 18 weeks were allocated to seven experimental groups, each of which included 5 replicates and reared upto 45 weeks of age. Experimental diets consisted of two protein diets along with 5 supplemental levels of tryptophan. The basal diet consisted of normal protein (CP-17 %) with 0.165 % tryptophan and low protein diet with 0.153 % tryptophan. Tryptophan was supplemented at 0.012, 0.015 and 0.035 % in normal protein diet to obtain 0.165 %, 0.18 % and 0.20 % digestible tryptophan and at 0.027 %, 0.047 % in low protein diets (CP- 16.23 %) to obtain 0.18 % and 0.20 % digestible tryptophan respectively. At the end of the study, six birds per treatment were dissected and morphological parameters such as total weight and length of oviduct were measured. For histological studies, after tissue preparation and staining with H and E, histological layers of magnum were recorded. The results of the present study indicated that the total weight and length of various segments of oviduct did not differ by tryptophan supplementation. In his to metrical studies, the length of primary mucosal folds of magnum was not altered by tryptophan supplementation.