Two experiments were carried out at the Poultry Sector of the School of Agrarian Sciences of the Federal University of Grande Dourados to evaluate the incidence of leg problems in broilers reared on two distinct types of bedding material: rice husks or wood shavings, both new and reused. In both trials, a randomized experimental design was applied in factorial arrangement (2 x 2 x 2) using two genetic strains (Cobb ® or Ross ® ); two sexes (male or female), and two litter materials (rice husks or wood shavings). In each trial 1080 one day pullets were reared equally divided in the treatments. The birds were placed in 4.5 m 2 boxes at a density of 10 birds m -2 . All birds were fed diets with equal nutritional density, and water was offered ad libitum. Feeds were divided in three phases: starter diet (1 -21 days), grower diet (22 -35 days), and finisher diet (36 -45 days). On day 45, fifty birds were randomly selected in each experiment to evaluate flock leg problems. The following parameters were analyzed: gait score, incidence of valgus and varus disorder, footpad dermatitis, femoral degeneration, tibial dyschondroplasia, and spondylolisthesis. Ambient temperature during rearing and litter caking and moisture content were recorded in four boxes per treatment. The analytical hierarchy process was used to organize the data into specific criteria. Several criteria, related to the attributes that were determinant according to the statistical analysis, were chosen in order to provide the best input to the process. Results indicated that new wood-shavings bedding was the most appropriate bedding to prevent locomotion problems, followed by new rice husks, reused wood shavings, and reused rice husks. However, when leg problems were associated to sex and genetic strain, male Ross birds strain presented less problems when reared on new rice husks, followed by new wood shavings

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The aim of this study was to evaluate the histological changes in the liver of thirty-five

RESUMO. Avaliou-se diferentes níveis de vitamina C na ração sobre a ocorrência de ectoparasitas, sobrevivência e biomassa total em alevinos de tilápia do Nilo, Oreochromis. Niloticus L. (Perciformes, Cichlidae) pós-revertidos, durante 57 dias. Alevinos com aproximadamente 0,30g e 24mm foram submetidos a 4 dietas contendo: 300 mg (T1), 600 mg (T2), 900 mg (T3) e 1200 mg (T4) de vitamina C por kg de ração. Inicialmente, a ocorrência de ectoparasitas foi de 100%, 38% de Trichodina e 62% de infecção mista (Trichodina + monogenéticos). Ao final não houve diferença significativa para ocorrência acumulada total, para Trichodina e infecção mista. Considerando a ocorrência dos monogenéticos, houve diferenças significativas entre o T1 e os demais. Em relação aos horários de coleta, foi encontrada uma diferença significativa na ocorrência entre o horário das 15h em relação aos demais horários. Em relação ao peso, comprimento médio total e padrão, biomassa e sobrevivência, não houve diferenças significativas. Conclui-se, então, que é desnecessário o uso de vitamina C em níveis superiores a 300mg/Kg de ração, sendo suficiente para atingir as exigências nutricionais a alevinos de tilápias criados em regime de manejo controlado. Palavras-chave:Oreochromis niloticus, vitamina C, ectoparasitas, alevinos, horário.ABSTRACT. Different vitamin levels C in the ration on the ectoparasitas occurrence, survival and total biomassa in Nile tilápia fingerlings (O. niloticus L.). Different vitamin levels C in the ration on the ectoparasitas occurrence, survival and total biomass in fingerlings of Nile tilápia Oreochromis. Niloticus L. (Perciformes, Cichlidae) were evaluated after sexual reversion, for 57 days. Fingerlings began the experiment with approximately 0,30g and 24mm and were submitted to four diets with 300-mg (T1), 600-mg (T2), and 900mg-(T3) e 1200-mg (T4) of vitamin C/kg of ration. In the beginning the ectoparasites occurrence was of 100%, 38,0% of Trichodina and 62,0% of mixed infection (Trichodina and monogenetics). At the end, there was not significant difference for total occurrence, for Trichodina and mixed infection. Considering the occurrence of the monogeneas there were significant differences between T1 and the others. In relation to the schedules of collection, a significant difference was found in the occurrence among the schedule of the 15:00 compared to the other schedules. No significant differences were observed in relation to weigh, total and standard medium length, biomass and survival, though. Results indicated that it is unnecessary to use vitamin C in superior levels to the 300-ration mg/Kg, enough to reach the tilápias fingerlings' nutritional needs, bred in controlled system.

Para estudar o manejo alimentar de alevinos de tilápia do Nilo (Perciformes, Cichlidae) foram estocados 1680 exemplares dessa espécie, com aproximadamente 24 mm de comprimento médio e 0,30 g de peso médio. Esses foram distribuídos em 24 caixas de água com capacidade de 250 L cada. Foram alimentados com ração comercial, sendo a mesma oferecida quatro vezes ao dia. O experimento foi constituído por quatro tratamentos, com diferentes níveis de vitamina C, com seis repetições cada. Foram analisadas as seguintes variáveis físicas, químicas e biológicas: temperatura do ambiente e da água, transparência, oxigênio dissolvido, níveis de amônia e níveis de nitrito presentes na água, pH, biovolume de fitoplâncton e de zooplâncton, período do dia, número da coleta e efeito do tratamento. Conclui-se que o grau de repleção do estômago (GR) é influenciado pela temperatura do ar, período do dia, temperatura da água, pH, biovolume do fitoplâncton e número da coleta. Os maiores valores para o GR foram obtidos nos horários mais quentes do dia, demonstrando que o consumo de alimento ocorre, preferencialmente, em temperaturas mais elevadas, o que coincide com o período de maior luminosidade, caracterizando a espécie como diurna. O tipo de alimento preferencial foi o artificial, seguido pelo fitoplâncton, que é consumido constantemente, confirmando a tendência fitoplânctófoga e filtradora da espécie. Palavras-chave: tilápia do Nilo, grau de repleção do estômago, fitoplâncton, zooplâncton, hábito alimentar. ABSTRACT. Feeding management of fingerlings of Nile tilapia Oreochromis niloticus (L.) associated with physical, biological and chemical variables of the environment. Feed management of 1680 Nile tilapia fingerlings (Perciformes, Cichlidae) with approximately 24 mm of mean length and 0.30g of mean weight is provided. The fingerlings were distributed in 24 tanks with 250 liters each. capacity each one. They were feed on a commercial diet four times a day. Four treatments with different levels of vitamin C and six repetitions constituted the experiment. Data of physical-chemical and biological variables, environment and water temperature, water transparency, dissolved oxygen, ammonium and nitrite levels in water, pH, phytoplankton and zooplankton biovolume, period of day, number collect and effect of treatment were analyzed. Stomach repletion degree is influenced by water and environment temperature, period of day, pH, phytoplankton and zooplankton biovolume and number of collect. Highest values of RD were obtained in the hottest hours of the day, which shows that the feed intake occurs in the highest temperature, coinciding with the time of the most intense light species characterized as diurnal. Artificial diet was preferred, followed by phytoplankton. This confirms the phytoplanktivorous habit of the specie, its diet and filtered, non-visual predation.