Intestinal and immunological histological parameters of broilers supplemented with commercial probiotic or fungi of the autochthonous microbiota

Abstract

This study aimed to assess the histomorphometry of the intestinal portions (duodenum and jejunum) in broilers supplemented with probiotic, and histological parameters of their immune system components. Rhizomucor spp. originated from samples of the intestinal content in Cobb 500 chickens was evaluated; these fungi were submitted to performance assay and selected based on in vitro probiotic characteristics. Complete randomized design was used (3 treatments × 7 replicates; 18 birds per experimental unit). One bird at 21 and 42 days of age was sacrificed in each unit and the organs were sampled. In all samples, fixation was conducted followed in order by dehydration and diaphanization; analyses were conducted by light microscopy and histomorphometry, and search was performed for spots indicating the lesion's presence. At 21 days, the duodenum villus height was higher in the group receiving Rhizomucor spp. probiotic, and the jejunum villus height was significantly increased in both the control and Rhizomucor spp. probiotic groups. At 42 days, difference of the duodenum crypt depth was observed in the group receiving commercial probiotic. With regard to the tissue changes of the intestines, spleen, and bursa, no histological alterations were observed at 21 days in all birds (100%) receiving Rhizomucor spp. probiotic, while alteration of the bursa was observed at 42 days in two animals. Inclusion of probiotic Rhizomucor spp. in the diet of broilers promoted an increase in the height of the villi after 21 days, and any influence of the probiotic was resolved after 42 days of age.