ABSTRACT The objective of this study was to evaluate the effects of different levels of microencapsulated carvacrol and cinnamaldehyde on metabolizable energy, feed digestibility, intestinal morphometric analysis, and antioxidant parameters in broilers. A completely randomized design with five treatments and eight replications of eight broilers (Cobb male) was used, and collections were carried out at 20 and 42 days of age. Carvacrol and cinnamaldehyde concentrations (mg/kg) were: 0 (control), 50, 100, 150, and 200. Carvacrol and cinnamaldehyde improved apparent metabolizable energy but did not change protein and ether extract digestibility. Supplementation increased intestinal villus height and villi:crypt ratio; in which 100 mg/kg produced the greatest villus height. Serum uric acid levels were lower in birds receiving supplementation. Improvement in the activity of glutathione peroxidase and glutathione-S-transferase was observed, while lower uric acid, thiobarbituric acid reactive substances, and reactive oxygen species levels were observed. Microencapsulated carvacrol and cinnamaldehyde improve apparent metabolizable energy and can be administered in broiler feed without risk to the bird’s health. These supplements may serve as alternative products to aid the performance of commercial poultry.

Abstract This study investigated injuries sustained by Pimelodus maculatus caused by transient operating conditions in a Brazilian hydroelectric power plant. Fish (n = 43) that inhabited the tailrace and appeared on the water surface after changes in the operating conditions were evaluated (IF). Additionally, fish (n = 10) captured using longline in the vicinity of the tailrace were used for comparisons (NF). Blood samples were evaluated for cortisol, glucose, and lactate concentrations. Tissue samples (gill, liver, brain, and muscle) were analyzed for oxidative stress biomarkers (TBARS, protein carbonyl content, and catalase activity) and histology (gill, liver, and spleen). The most prominent findings in IF were barotraumas with intra-abdominal hemorrhage and swim bladder rupture. Cortisol and glucose concentrations were lower for IF when compared to NF. IF also suffered from oxidative stress, as indicated by increased TBARS in the liver and brain, as well as increased protein carbonyl content in the gills and liver. The main histological alterations induced by the adverse conditions were circulatory disorders, such as telangiectasia and gill aneurysm, hepatic congested veins, and hemorrhage in the liver and spleen. The abrupt drop of pressure resulting from changes in the operating conditions of the turbines caused barotraumas and oxidative stress, which were the leading causes of fish mortality

Resumo Este estudo investigou os efeitos induzidos por condições transitórias de operação em uma usina hidrelétrica brasileira em Pimelodus maculatus. Peixes (n = 43) no canal de fuga que apareceram na superfície da água após mudanças nas condições operacionais foram avaliados. Adicionalmente, peixes (n = 10) capturados a jusante da barragem com espinhel foram utilizados para comparações (NF). Amostras de sangue foram avaliadas para as concentrações de cortisol, glicose e lactato. Amostras de tecidos (brânquia, fígado, cérebro e músculo) foram analisadas para biomarcadores de estresse oxidativo (TBARS, conteúdo de proteína carbonil e atividade da catalase) e histologia (brânquia, fígado e baço). Os achados mais proeminentes dos peixes afetados (IF) foram barotraumas com hemorragia intra-abdominal e ruptura da bexiga natatória. As concentrações de cortisol e glicose foram menores para IF quando comparadas aos NF. IF também sofreram estresse oxidativo representado pelo aumento de TBARS no fígado e cérebro, e aumento do conteúdo das proteínas carboniladas nas brânquias e fígado. As principais alterações histológicas induzidas pelas condições adversas foram distúrbios circulatórios, como telangiectasia e aneurisma nas brânquias, congestão das veias hepáticas, e hemorragia no fígado e baço. A queda abrupta da pressão resultante de mudanças nas condições operacionais das turbinas causou barotrauma e estresse oxidativo, que foram as principais causas da mortalidade dos peixes.