Alternative Methods to Control Necrotic Enteritis

AUSTRALIA - A probiotic and an organic acid blend did not prevent necrotic enteritis but some improvements were evident, report researchers based in Adelaide.

1 July 2010

3 minute read

Oceania

M.S. Geier of the University of Adelaide and co-authors from across Australia and Canada have investigated alternatives to in-feed antimicrobials for the prevention of clinical necrotic enteritis in broilers, and their paper is soon to be published in Journal of Applied Microbiology.

The aim of their work, they explain, was to examine the capacity for a probiotic (Lactobacillus johnsonii) and an organic acid (OA) blend to prevent Clostridium perfringens-induced clinical necrotic enteritis in chickens.

Cobb 500 birds were allocated into six groups (n=25 birds per pen, eight pens per treatment). The six treatments were: Unchallenged, Challenged, Antimicrobial (zinc bacitracin (ZnB)/monensin), OA, probiotic Lact. johnsonii and probiotic sham (phosphate–buffered saline). All birds were challenged with Eimeria spp. and Cl. perfringens except for the unchallenged controls.

Birds fed antimicrobials were protected from necrotic enteritis development as indicated by maintenance of body weight, low mortality and Clostridium levels, and decreased intestinal macroscopic lesion scores compared to challenged controls (P<0·05).

Lact. johnsonii-fed birds had reduced lesion scores, whilst OA-fed birds had decreased Cl. perfringens levels.

Both Lact. johnsonii and OA-fed birds had improved feed efficiency between days 0 and 28 compared to challenged controls. however, mortality and body weights were not improved by either treatment.

Microbial profiling indicated that the challenge procedure significantly altered the jejunal microbiota. The microbiota of antimicrobial-fed birds was significantly different from all other groups.

Geier and co-authors concluded that whilst Lact. johnsonii and OA altered specific intestinal parameters, no significant protection against necrotic enteritis was observed.

They explained that Lact. johnsonii and OA did not prevent necrotic enteritis but that some improvements were evident. Other related treatments, or combinations of these two treatments, may provide greater protection, they added.

Reference

Geier M.S., L.L. Mikkelsen, V.A. Torok, G.E. Allison, C.G. Olnood, M. Boulianne, R.J. Hughes and M. Choct. 2010. Comparison of alternatives to in-feed antimicrobials for the prevention of clinical necrotic enteritis. Journal of Applied Microbiology. (online ahead of publication). DOI 10.1111/j.1365-2672.2010.04758.x.