RESUMO
Clostridium perfringens is the etiological agent of NE, a disease that greatly affects the poultry industry. Experiments on the induction of NE are difficult to carry out, as it is a multifactorial disease, and thus different predisposing factors have been used. This study evaluated the effect of the Gumboro disease vaccine virus vaccine (IBDV-vac) associated or not with infection by Eimeria spp. in broilers, as a predisposing factor for NE. Broilers (n = 99) were divided into groups (11) challenged with IBDV-vac, Eimeria spp. CP type G (CP13, CP14 and CP03) or both. The macroscopic evaluation revealed that the highest average (3.45) of injury occurred for the CP13 + IBDV-vac group. The microscopic analysis showed that Eimeria spp. increased the population of intraepithelial lymphocytes and reduced the villus/crypt ratio in duodenum and jejunum when associated with CP13 or CP14. There was a synergistic effect between the CP strain used and the predisposing factors; nevertheless, it was not clear which was the most effective predisposing factor to potentiate the lesions, suggesting that the association of the strain with the factors should first be evaluated for each experimental protocol.
RESUMO
The mycotoxin deoxynivalenol (DON) contaminates animal feed worldwide, frequently resulting in poor performance and economic losses. Data concerning the effects on poultry health or focusing on intestinal toxicity or the response to oxidative stress are scarce. Also, there is a need for strategies to mitigate the negative effects of DON. This study aimed to investigate the effects of Lactobacillus spp. treatments on the intestine, liver and kidney of poultry fed a DON-contaminated diet. To achieve this aim, histological, morphometrical and histochemical assays were performed. The oxidative stress response was also analyzed by the tests: reduced glutathione, ferric reducing ability, reducing of 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulphonic acid), nitro blue tetrazolium detection of superoxide anion, and thiobarbituric acid reactive substances. One-day-old broilers chickens (n 50) were submitted to the following treatments: control, DON (19.3 mg kg-1), viable Lactobacillus spp. + DON (VL + DON), heat-inactivated Lactobacillus spp. + DON (HIL + DON), Lactobacillus spp. culture supernatant + DON (LCS + DON). The animals received the contaminated diet for seven days. DON increased the intestinal and liver lesion score, while the Lactobacillus spp. treatments (LT) remained like the control. DON reduced the villi height and increased the crypt depths. The LT showed crypt depths similar to control, and higher villi: crypt ratio in duodenum and jejunum. In the ileum, the LT reduced the goblet cell count in relation to DON group. DON increased the number of intraepithelial lymphocytes (IEL) in jejunum and ileum, while the VL + DON treatment induced a significant decrease in IEL in comparison to DON. DON-diet induced an oxidative stress response in the intestine and liver, and also reduced the antioxidant capacity in these tissues, while LT treatments remained mostly similar to control. DON induced no change in redox balance in the kidney. The LT improved the intestinal health after DON acute exposure, reducing the oxidative stress damage mainly on jejunum and liver.
