Morphometric Analysis of the Intestine in Experimental Coccidiosis in Broilers Treated with Anticoccidial Drugs.

Background: Coccidiosis causes morphologic alteration in intestinal mucosa resulting in reduction of absorptive surface. Anticoccidials used as feed additives may induce changes in the intestinal mucosa. This study was designed to assess intestinal morphometry in broilers infected with under different anticoccidial treatments.

Methods: To evaluate the effect of salinomycin and amprolium+ethopabate on intestinal morphometry in broilers experimental coccidiosis, in Tehran, Iran in May 2015, fifty-four Ross 308 birds were randomly divided into two challenged and unchallenged groups at the age of 12 days. The birds were challenged with field isolate at day 14. Different growth and parasitological parameters including weight gain, feed consumption, FCR, macroscopic lesion score and oocyst score were recorded 7 d post-inoculation. Histological sections from four main parts of intestine (anterior, middle, lower intestines and cecum) were prepared and analyzed. Villus width and length and total mucosal thickness were measured microscopically.

Results: Amprolium+ethopabate and salinomycin significantly reduced coccidiosis gross lesions in infected birds. Microscopically anticoccidial administration in the presence of infection has significantly increased the villus length while the presence of amprolium+ethopabate in the absence of infection has greatly increased the mucosal thickness and villi height in comparison to the control group.

Conclusion: Anticoccidials may induce some histological changes in the mucosa when there is no parasite to be affected. Some of these effects may be advantageous for the intestinal epithelium integrity and hence the birds' performance.