Effect of an organic acids and medium-chain fatty acids containing product in feed on the course of artificial Necrotic Enteritis infection in broiler chickens.

The effect of an organic acids (OA) and medium-chain fatty acids (MCFA) containing product was tested on the course of artificial Necrotic Enteritis infection in broiler chickens at 2 and 5 kg/ton. Three control groups were used: 1. a non-infected non-medicated group; 2.an infected non-medicated group and 3. an infected medicated group (50 g/ton BMD). Two kg/ton of the OA/MCFA product significantly reduced the incidence of intestinal NE lesions by 22% as compared to infected, non-medicated control group. Weight gain (0-28 days) was improved by 29% and Feed conversion ratio (0-28 days) by 8%; total NE mortality was reduced by 43%. A dosage of 5 kg/ton of OA/MCFA product did not further improve parameters. Also BMD significantly improved performance and NE lesions. It is concluded that the tested OA/MCFA product shows mild anti-Clostridium effects in vivo and fits well in a total approach to control NE; the recommended dosage is 2 kg/ton. Introduction Necrotic enteritis (NE) in broiler chickens is caused by Clostridium perfringens. This disease has a large negative impact on the health of broilers and therefore on the profitability of commercial broiler operations. After the ban on antimicrobial growth promoters (AMGP), it is expected that incidence of NE will increase. Organic acids (OA) have been used for decades due to its preservative (flora modulating) effects in feed and subsequently in the first parts of the gastro-intestinal tract. Medium-chain fatty acids (MCFA) recently have caught scientific interest due to its antibacterial effects (Stratford and Anslow, 1996; Van Immerseel et al., 2004). In this research a product combining organic acids (formic, acetic, propionic, and sorbic acid) and medium-chain fatty acids (caprylic, and capric acid) was tested. In vitro research had already indicated a strong anti-Clostridium effect of this product (MIC value of 0.15%; Corujo Fernandez, 2004, Nutreco internal report). A next step was to test the effect of this product in vivo. We used an experimental model with a two-step infection, first with Eimeria challenge and successively with Clostridium perfringens. The animal performance and intestinal NE lesion score were measured. The hypothesis was that the experimental product would improve these parameters compared to an infected control group without additives; a medicated group with 50 g/ton of growth promoter Bacitracin Methylene Disalicylate (BMD) was also tested. Materials and Methods The experiment was carried out at the Southern Poultry Research Centre, Athens, USA. Five experimental treatments were tested: 1 Selacid Green Growth Poultry MP, Selko BV, Tilburg, The Netherlands.