Efeitos das aflatoxinas no pâncreas exócrino e desempenho de frangos de corte

Abstract

Several studies have related the problems with the health of poultry production with poisoning resulting from ingestion of aflatoxins. However, there is a need to conduct further research to deepen knowledge of the effects of aflatoxin on the systems involved in digestion and utilization of the diet ingredients, with this, the objective of this study was to evaluate the effects of aflatoxin weekly on the activity of digestive enzymes (α-amylase, lipase and trypsin) in the pancreas, zootechnical parameters at the end of each stage of production and histology of pancreas of broilers intoxicated for 42 days of experiment. For this, we used 1080 broiler chicks, the Cobb males, 1 day old. Was completely randomized experimental design, in which the birds were divided into four treatments with 18 replications. Each replication consisted of 15 birds, totaling 270 animals per treatment. The treatments were defined as the concentration of added dietary aflatoxin: T1 = 0 mg / kg of aflatoxin in feed, T2 = 0.7 mg / kg of aflatoxin in feed; T3 = 1.7 mg / kg of aflatoxin in feed and T4 = 2.8 mg / kg of aflatoxin in feed. The samples of the pancreas were performed in a bird each repetition, chosen at random, at 7, 14, 21, 28, 35 and 42 days, totaling eighteen birds per treatment. The pancreas of each bird was homogenized with distilled water, frozen in liquid nitrogen, lyophilized and stored at -20 °C. Feed intake, body weight and feed conversion were measured at 21, 35 and 42 of the experiment. Fragments of pancreas of 6 birds from each treatment were collected at 42 days of age, maintained in 10% formalin for histopathological evaluation. The inclusion of aflatoxins in the diet caused a significant increase in the activities of the enzymes α-amylase and lipase in treatments T3 and T4. The specific activity of trypsin only significant difference in treatment T4. Aflatoxins induced negative effect on live performance, as well as histopathological changes affecting the exocrine pancreas of birds. The pancreatic enzymes play a crucial role in digestion and absorption of ingested macromolecules, so the influence on the activity of these enzymes caused by aflatoxins directly affects the digestibility of the diet leading to losses in productivity of animals.