ABSTRACT Industrial broilers raised on helminthic medication-free feed were diagnosed with a severe disease caused by Ascaridia galli, characterized by intestinal hemorrhage and obstruction. A. galli was identified based on the morphological features of the nematode. Broilers were raised for a longer period (63 days) for weight recovery, grouped as stunted (n=500), had low body score and had fetid diarrhea. The duodenum-jejunum segment was the most severely affected with obstruction and had localized accumulation of gas. The intestinal mucosa was severely congested with petechial and suffusive hemorrhages. The outbreak resulted in morbidity of about 10% and mortality of up to 4% and was associated to the absence of preventive medication on feed and slack biosecurity. The reemergence of A. galli is discussed in view of the alternative poultry management and raising conditions for drug free and welfare.

No presente estudo, foram utilizados testes de velocidade fixa e progressiva em um aparato experimental baseado no respirômetro de Brett, para examinar as velocidades prolongada e sustentável do mandi-amarelo, Pimelodus maculatus. Quando comparadas as curvas de velocidade crítica versus o comprimento do corpo entre o mandi e o salmão Oncorhynchus nerka, é observado que, para um mesmo comprimento, o mandi apresenta velocidades superiores, provavelmente devido a diferenças na temperatura da água. Foram estimadas a velocidade sustentável da espécie em cinco comprimentos por segundo e a porcentagem de peixes fatigados ao longo do tempo em uma dada velocidade estimada. Os dados obtidos para o mandi representam uma importante contribuição para o manejo da espécie, provendo critérios de projeto para a construção de estruturas como mecanismos de transposição e sistemas de proteção e orientação.

The present study used fixed and increasing velocity tests in an experimental apparatus based on Brett's respirometer to examine prolonged and sustained speeds of the "mandi-amarelo", Pimelodus maculatus. When comparing the curves of critical speed versus total length between the mandi and the sockeye salmon Oncorhynchus nerka, it is observed that for an equal total length, the mandi presents a greater speed, probably due to water temperature differences. The sustained speed for the species was estimated in 5 lengths per second and the percentage of fatigued fish within time in a certain velocity was established. The data raised for the mandi represents an important contribution to the improvement of the handling of the species, providing guidance and criteria for designing several structures, such as fishways, fish screens and guidance systems.