The aim of this research was to evaluate, on a weekly basis, the effects of aflatoxins on the activity of digestive enzymes (alpha-amylase, lipase, and trypsin) in the pancreas as well as on the performance and histology of pancreas in broiler chickens over the course of 42 days. One thousand and eighty 1-day-old male Cobb broilers were divided into four treatments with 18 replicates and 15 birds per replicate (i.e., 270 broilers per treatment). Treatments were established according to the amount of aflatoxins added to the diet, as follows: T1 = 0 mg of aflatoxins per kilogram of feed (mg/kg); T2 = 0.7 mg/kg; T3 = 1.7 mg/kg; and T4 = 2.8 mg/kg. Pancreas sample collection was performed from one bird out of each replicate at 7, 14, 21, 28, 35, and 42 days of experiment, which yielded a total of 18 samples per treatment on each collection. Each sample was homogenized in distilled water, frozen in liquid nitrogen, lyophilized, and stored at -20 C until analysis. Performance parameters (body weight, feed consumption, and feed conversion rate) were measured at 21, 35, and 42 days of experiment. At the end of the experiment (42 days), six birds from each treatment were randomly chosen for histologic evaluation of the pancreas. The presence of aflatoxins in the diet induced a negative effect on all performance parameters. The pancreatic activity of lipase and alpha-amylase were significantly increased in treatments T3 and T4, while the specific activity of trypsin was only affected during treatment T4. In addition, several histologic changes were observed in the pancreas of birds receiving aflatoxin-contaminated feed. Aflatoxins present in the feed determined an increase in the activity of pancreatic enzymes in broilers, affecting the digestibility of the diet, thereby leading to losses in performance and productivity.

The aim of this research was to evaluate the individual and combined effects of Salmonella typhimurium lipopolysaccharide (sLPS) and fumonisin B(1) (FB) on performance, relative weight of liver, biological parameters, and histological evaluation of several tissues from four hundred thirty-two 1-d-old male broiler chickens divided into 9 treatments according to the dose of FB (0, 100, or 200 mg/kg, from d 1 to d 28) and sLPS (0, 250, or 500 µg/application per bird, every other day, from d 15 to 27) administered. At the end of the experiment (28 d), significant effects caused by sLPS, FB, and the interaction of sLPS × FB were observed on several parameters. Histopathological evaluations showed significant lesions in liver and kidney caused by sLPS, FB, and their association. According to these results, both sLPS and FB (isolated or in association) cause significant effects on performance and biological parameters of broilers at 28 d of age.

Variance and performance of two sampling plans for aflatoxins quantification in maize were evaluated. Eight lots of maize were sampled using two plans: manual, using sampling spear for kernels; and automatic, using a continuous flow to collect milled maize. Total variance and sampling, preparation, and analysis variance were determined and compared between plans through multifactor analysis of variance. Four theoretical distribution models were used to compare aflatoxins quantification distributions in eight maize lots. The acceptance and rejection probabilities for a lot under certain aflatoxin concentration were determined using variance and the information on the selected distribution model to build the operational characteristic curves (OC). Sampling and total variance were lower at the automatic plan. The OC curve from the automatic plan reduced both consumer and producer risks in comparison to the manual plan. The automatic plan is more efficient than the manual one because it expresses more accurately the real aflatoxin contamination in maize.

RESUMO O objetivo deste trabalho foi avaliar a eficiência de dois planos de amostragem para análise de fumonisinas