In this study we assessed the roles of Eimeria infection and dietary manipulation (feeding a diet with a high level of fishmeal) in an Australian necrotic enteritis (NE) challenge model in broiler chickens. An experiment was designed to test the hypothesis that Eimeria infection and dietary manipulation, i.e., inclusion of fishmeal in the diet, are necessary to induce NE experimentally. The results showed that the combination of Eimeria administration and fishmeal feeding had a significant effect on induction of clinical and subclinical Clostridium perfringens infection. The majority of the mortality that occurred during the second week of the trial was due to an NE outbreak following the C. perfringens challenge. The mortality rate of the birds was 12.00% for the high-fishmeal (HFM; 500 g/kg) group and 9.33% for the low-fishmeal (LFM; 250 g/kg) group when the birds were subjected to C. perfringens and Eimeria. Fishmeal alone did not induce significant mortality in birds challenged only with C. perfringens but showed a significantly higher C. perfringens count than the non-fishmeal (NFM) control group. Eimeria administration had a significant effect on NE-related mortality but did not have an effect on the C. perfringens count. In accordance with the time course of bird mortality, it can be determined that of the 3 successive days of oral gavage with C. perfringens, the first inoculation was essential for inducing NE, but the third had no additional effect on NE-related mortality. Also, reducing the fishmeal level from 500 to 250 g/kg had no negative impact on the reproducibility of the model. It may be concluded that NE can be consistently induced under experimental conditions by feeding broilers a diet containing 250 g/kg fishmeal, using a single inoculation with low numbers of Eimeria, administering one or two oral C. perfringens inoculations, and maintaining appropriate ambient temperatures and diets.
You have requested a machine translation of selected content from our databases. This functionality is provided solely for your convenience and is in no way intended to replace human translation. Neither BioOne nor the owners and publishers of the content make, and they explicitly disclaim, any express or implied representations or warranties of any kind, including, without limitation, representations and warranties as to the functionality of the translation feature or the accuracy or completeness of the translations.
Translations are not retained in our system. Your use of this feature and the translations is subject to all use restrictions contained in the Terms and Conditions of Use of the BioOne website.
Vol. 54 • No. 3