ABSTRACT The objective of this study was to evaluate live weight and carcass traits, from birth to slaughter, and meat quality of Nellore (NEL), Curraleiro Pé-Duro (CPD), and crossbred (F1) products in the state of Piauí, Brazil. Progenies from CPD, NEL, and their F1 crossbred (½ NEL + ½ CPD), a total of 252, males and females, from birth to 24 months of age, were evaluated in a comparative study in growth performance. The steers were sent to slaughter at 28 months of age and carcasses and meat quality were analyzed. After slaughter, carcass weight, dressing percentage and Longissimus dorsi area (rib eye area) were evaluated; an index was created by the relationship between these measures per hundred kg of chilled carcass produced. To assess meat quality, the shear force, water-holding capacity, color, brightness, pH, and cooking loss were investigated. Results obtained showed that month and year of birth were significant on growth, indicating influence of climatic variables. Nellore offspring was heavier than F1 and this was heavier than CPD throughout the study period, including the hot and cold carcass. No differences were found in dressing percentage among NEL and F1, but CPD and F1 showed a rib eye area and index significantly higher than NEL. The meat from CPD group presented a stronger red coloration than the others, but there was no significant difference in the remaining meat qualitative variables among the three groups. Curraleiro Pé-Duro and F1 crossbred produce more meat per 100 kg of carcass than Nellore in natural pasture of Piauí State.

Foram observadas algumas características de populações locais de Panstrongylus megistus e de mamíferos domiciliados e silvestres. Confirmou-se o papel das matas residuais na permanência local da população triatomínica, bem como o caráter agrupado da dispersão do inseto com nítida preferência pelos anexos domiciliares. Observou-se apreciável ecletismo alimentar do vetor e a ocorrência de multiplicidade na utilização de fontes sanguíneas, o que lhe confere considerável amplitude na sua valência ecológica local. Evidenciou-se a presença de ciclos enzoóticos silvestres e domiciliados indicando a clara possibilidade de reintrodução da tripanossomíase no ambiente humano direto. Conclui-se pela necessidade de manutenção da vigilância epidemiológica a ser cuidadosamente estudada face aos aspectos locais da parasitose.

Several characteristics of local Panstrongylus megistus and vertebrate populations related to the artificial and natural ecotopes were observed. The role of the remaining forest spots as shelter places for triatomid bugs and vertebrate reservoirs was confirmed. The contagious or grouped type bug dispersion was clearly observed, with a high preference for inhabiting peridomiciled dwellings. The local bug feeding pattern showed a high frequency of mixed blood sources thus pointing out a great feeding mobility. With the natural infected bugs, this pattern showed association with mammal blood, particularly marsupial (Didelphis) and rodent (Rattus). Enzootics of the trypanosomiasis were detected in the sylvatic and domiciliary environments. They were considered as potentially dangerous as regards reproduction of the infection in the local human environment. Careful epidemiological surveillance studies will be necessary due to local characteristics of this parasitosis.

Foram observadas algumas características de populações locais de Panstrongylus megistus e de mamíferos domiciliados e silvestres. Confirmou-se o papel das matas residuais na permanência local da população triatomínica, bem como o caráter agrupado da dispersão do inseto com nítida preferência pelos anexos domiciliares. Observou-se apreciável ecletismo alimentar do vetor e a ocorrência de multiplicidade na utilização de fontes sanguíneas, o que lhe confere considerável amplitude na sua valência ecológica local. Evidenciou-se a presença de ciclos enzoóticos silvestres e domiciliados indicando a clara possibilidade de reintrodução da tripanossomíase no ambiente humano direto. Conclui-se pela necessidade de manutenção da vigilância epidemiológica a ser cuidadosamente estudada face aos aspectos locais da parasitose.

Several characteristics of local Panstrongylus megistus and vertebrate populations related to the artificial and natural ecotopes were observed. The role of the remaining forest spots as shelter places for triatomid bugs and vertebrate reservoirs was confirmed. The contagious or grouped type bug dispersion was clearly observed, with a high preference for inhabiting peridomiciled dwellings. The local bug feeding pattern showed a high frequency of mixed blood sources thus pointing out a great feeding mobility. With the natural infected bugs, this pattern showed association with mammal blood, particularly marsupial (Didelphis) and rodent (Rattus). Enzootics of the trypanosomiasis were detected in the sylvatic and domiciliary environments. They were considered as potentially dangerous as regards reproduction of the infection in the local human environment. Careful epidemiological surveillance studies will be necessary due to local characteristics of this parasitosis.

Foi salientado que, em certas áreas, os métodos de rotina no controle dos vetores da doença de Chagas necessitam ser complementados por atividades de captura de resrevatórios do T. cruzi, especialmente no caso, marsupiais (Didelphis) e roedores (Rattus). Foram citados trabalhos realizados em alguns municípios da Região Administrativa 5 - Campinas, Estado de São Paulo, Brasil, onde a presença de reservatórios e triatomíneos semi-domiciliários (Panstrongylus megistus), nas moradias, propiciam condições à reintrodução do ciclo domiciliar do parasita. São comentados os resultados da pesquisa do Trypanosoma tipo cruzi, nesses triatomíneos e nos citados vertebrados, relacionando ainda os resultados com as reações de precipitina realizadas no sentido de detectar o tipo de sangue ingerido pelos P. megistus capturados.

Emphasis is layed upon the fact that in some areas, the routine methods used to control vectors of Chagas' disease, must be complemented by seizure activities of T. cruzi reservoirs, specially marsupials (Didelphis) and rodents (Rattus). A study was undertaken in some municipal districts of the Administrative Region of Campinas, State of S. Paulo, where the presence of reservoirs and peridomestic triatomines (Panstrongylus megistus) allow favourable conditions for the reintroduction of the domiciliary parasitic cycle. The results of the search of Trypanosoma type cruzi in these triatomines and the mentioned reservoirs are commented. Their association with the precipitin reaction in order to allow detection of the type of blood ingested by the P. megistus captured in the houses was studied.

Foi salientado que, em certas áreas, os métodos de rotina no controle dos vetores da doença de Chagas necessitam ser complementados por atividades de captura de resrevatórios do T. cruzi, especialmente no caso, marsupiais (Didelphis) e roedores (Rattus). Foram citados trabalhos realizados em alguns municípios da Região Administrativa 5 - Campinas, Estado de São Paulo, Brasil, onde a presença de reservatórios e triatomíneos semi-domiciliários (Panstrongylus megistus), nas moradias, propiciam condições à reintrodução do ciclo domiciliar do parasita. São comentados os resultados da pesquisa do Trypanosoma tipo cruzi, nesses triatomíneos e nos citados vertebrados, relacionando ainda os resultados com as reações de precipitina realizadas no sentido de detectar o tipo de sangue ingerido pelos P. megistus capturados.

Emphasis is layed upon the fact that in some areas, the routine methods used to control vectors of Chagas' disease, must be complemented by seizure activities of T. cruzi reservoirs, specially marsupials (Didelphis) and rodents (Rattus). A study was undertaken in some municipal districts of the Administrative Region of Campinas, State of S. Paulo, where the presence of reservoirs and peridomestic triatomines (Panstrongylus megistus) allow favourable conditions for the reintroduction of the domiciliary parasitic cycle. The results of the search of Trypanosoma type cruzi in these triatomines and the mentioned reservoirs are commented. Their association with the precipitin reaction in order to allow detection of the type of blood ingested by the P. megistus captured in the houses was studied.