Effect of dietary Azolla supplementation on growth performance and histomorphometric features of the small intestine in broilers

This study was carried out to investigate the effects of Azollapinnata supplementation on growth performance and intestinal histomorphometric parameters in broilers. A total of 480 day-old male broiler chicks (BW = 38.85 +/- 0.16 g) were assigned to four groups for eight replicates (15 chicks for each). Chicks in the control group were fed basal diet, and experimental groups were fed diets containing Azolla (AZL) at a rate of 3% (AZL3), 4% (AZL4) and 5% (AZL5), respectively during 21 days. At the end of the experiment (day 21), the AZL3 group had significantly higher body weight than the control and other experimental groups. A significant decrease in body weight values was found when the amount of Azolla in the diets increased above 3%. No significant difference between the control and AZL3 group for average daily gain between days 0-21, but AZL4 and AZL5 groups had a significantly lower average daily gain compared to these two groups. Compared to the other experimental groups and the control group, the feed conversion rate significantly improved in the AZL3 group. According to histomorphometric data of duodenum, jejunum and ileum tissue samples obtained from the groups at the end of the experiment, it was determined that AZL3 had significantly higher villus height, villus width, villus surface area, villus height to crypt depth ratio, thickness of Tunica muscularis and Tunica mucosa, and lower crypt depth than the control and other experimental groups. As a result of this sudy, Azolla supplementation exceeding 3% to broiler diets had no significant advantage on both performance and intestinal histomorphometric parameters.