Use of tannins as an alternative to antimicrobials to control avian necrotic enteritis in poultry production

REDONDO, E A; REDONDO, L M; CABRAL, C; BATISTA, J; DOMINGUEZ, J E; FERNANDEZ MIYAKAWA, ME

Florionapolis

Congreso; 28º Congresso Brasileiro de Microbiologia.; 2015

Sociedade Brasileira de Microbiologia

Clostridial enteric diseases in poultry are mainly caused by Clostridium perfringens. Traditionally,the level of this microorganism in the gut of chickens has been controlled by antibiotics included inthe formulation of the feed as growth-promoting factors (GPF) to improve growth and to reduceproduction costs. In the lasts years, several countries banned the use of antimicrobials as GPF andthus alternatives should be evaluated. Tannins are polyphenolic compounds present in many plantsconsumed daily by humans and animals. Previous studies show that tannins from different sourcesmay have antibacterial or antitoxic activity and they are able to prevent the development ofclostridial enteric diseases when added into the feed. The aim of this study was to determine theeffect of the addition of tannins to assess whether they can be used to control the development ofenteric diseases produced by different agents. Two independent trials were carried out incommercial broiler chicken farms located in Santa Catarina, Brazil and Buenos Aires, Argentina.Each trial considered a total of circa 2,000,000 birds under commercial productive conditions. Inorder to evaluate the effect of tannins on the productive parameters, in each trial chickens fromtreated farms were provided commercial feed added with a commercial mixture of tannins while incontrol farms chickens only received regular feed and were considered as control. Differentparameters were analyzed including mortality, weight gain and presence of undigested feed infeces. On days 21 and 26, 10 animals were randomly selected from 1 house of each farm and werenecropsied. Presence and severity of lesions was recorded using a score ranging from 0 to 5 (0: nolesions; 5: massive necrosis). In addition, histomorphometry was done in different sections of smallintestine. In both trials results show that tannins were able to reduce both the frequency the severityof the lesions. Significant differences between chickens fed with or without tannins were found inthe score of lesions observed in the duodenum, jejunum and ileum. Also histomorphometricparameters were improved in chickens that received tannins as additive. These results demonstratethat addition of tannins in the diet of poultry is a promising alternative to antimicrobial GPF and canbe used as a strategy to control necrotic enteritis in chickens by reducing clinical signs and impacton production parameters.