Dietary ethylenediamine dihydroiodide mitigated Escherichia coli O78-induced immune and intestinal damage of ducks via suppression of NF-κB signal.

This study investigated the effect of Ethylenediamine dihydroiodide (EDDI) on growth performance, immune function and intestinal health of meat ducks challenged with Avian pathogenic Escherichia coli (APEC). A total of 360 one-day-old Cherry Valley ducks with similar body weight were randomly allocated to 6 treatments (6 floor cages, 10 birds/cage). A 3 × 2 factor design was used with 3 dietary iodine levels (0, 8, 16 mg/kg in the form EDDI and whether APEC was challenged or not at 7-day-old ducks. The feeding period lasted for 20 d. The results showed that the addition of EDDI reduced APEC-induced decrease of the 20-d weight loss of meat ducks (P < 0.05), and alleviated the inflammatory response of liver tissue induced by APEC challenge in meat ducks. In terms of immune function, EDDI supplementation reduced the immune organ index and increased the immune cell count of meat ducks, reduced the level of endotoxins in the serum of meat ducks (P < 0.05), as well as inhibited the expression levels of liver and spleen inflammatory factors and TLR signaling pathway related genes induced by APEC (P < 0.05). In terms of intestinal health, EDDI inhibited APEC-induced decreases in ZO-3 genes expression and increases in IL-1ß and TNF-α expression, increased relative abundance of beneficial bacteria in the cecum and content of metabolites. Pearson correlation analysis showed that there was a significant correlation between liver inflammatory factors and TLR4 signaling pathway genes, and there might be a significant correlation between intestinal microbial flora and other physiological indexes of meat ducks, which indicated that EDDI could reduce the damage to immune function and intestinal health caused by APEC challenge through regulating the structure of intestinal flora. Collectively, our findings suggest that the EDDI can promote growth performance, improve immune function and the intestinal barrier in APEC-challenged meat ducks, which may be related to the suppression of NF-κB signal.

Prediction of the Net Energy of Wheat from Chemical Analysis for Growing Ducks.

The goal of this study was to determine the net energy (NE) value of wheat for growing ducks and establish a NE prediction equation based on the grain's chemical composition. Forty wheat samples were selected based on bulk weight from major wheat-producing regions in China. A total of 460 1-week-old ducks (initial body weight (BW): 134.86 ± 3.32 g) were randomly assigned to 46 diets, including a basal diet, 5 restricted feeding diets and 40 test diets. Each diet contained five replicates, each with two ducks. The basic diet was a corn-soybean meal, and 40 kinds of experimental diets were prepared by mixing the basic diet with 20% wheat. A prediction equation for the NE concentration was created using the chemical make-up of wheat samples. The results indicated that the NE and apparent metabolism energy (AME) content of 40 wheat samples ranged from 6.81 to 9.12 MJ/kg and from 11.03 to 14.34 MJ/kg, respectively. The ether extract (EE), neutral detergent fiber (NDF), acid detergent fiber (ADF) and AME were highly correlated with NE value (p < 0.01), with the AME and NE showing the strongest correlation (r = 0.884). Chemical features could be used to predict the NE values with accuracy, and the prediction equation was strengthened by the inclusion of the AME. The best-fit equation was as follows: NE = 0.380 AME - 0.147 NDF - 0.274 ADF + 5.262 (R2 = 0.874, RSD = 0.19, p < 0.001). In summary, the NE value of wheat is 8.49 ± 0.30 MJ/kg for growing ducks, and the chemical composition can be used to accurately predict NE in wheat.