936 resultados para Net-cages


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Pós-graduação em Zootecnia - FCAV

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Pós-graduação em Aquicultura - FCAV

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Este trabalho objetivou verificar se o ultrassom de baixa potência (US) previne a ocorrência de osteopenia em tíbias de ratos sob ausência de carga. Foram utilizados 45 Rattus novergicus albinus, Wistar adultos, machos, distribuídos em cinco grupos iguais: C - animais-controle livres em gaiolas por 21 dias; S - animais suspensos pela cauda por 21 dias; ST - suspensos pela cauda por 21 dias e concomitantemente tratados com US; S→C - suspensos por 21 dias e depois permanecendo livres em gaiolas por mais 21 dias; S→CT - suspensos por 21 dias e depois permanecendo livres em gaiolas por mais 21 dias e concomitantemente tratados com US. O tratamento foi realizado com US de 1,5MHz, ciclo de trabalho 1:4, 30mW/cm², na tíbia direita, por 15 sessões de 20 minutos cada, cinco sessões por semana. Ainda vivos, os animais foram submetidos a exame de densitometria óssea para verificação da densidade mineral óssea (DMO) e do conteúdo mineral ósseo (CMO). Após a eutanásia dos animais, as tíbias foram desarticuladas, dissecadas e submetidas a ensaio mecânico destrutivo para análise da força máxima (Fmáx) e da rigidez (R). Foram avaliados também o comprimento (L) e o diâmetro (D) no ponto médio da tíbia. O grupo S apresentou valores de DMO, CMO, Fmáx, R, L e D menores em relação ao grupo C, demonstrando que a suspensão pela cauda é prejudicial a estas variáveis. O tratamento dos animais suspensos com o US, grupo ST, elevou os valores de CMO e DMO em relação aos do grupo S, igualando-os aos do grupo C. A Fmáx, R e L do grupo ST aumentou em relação ao grupo S e também em relação ao grupo C (p<0,05). Nenhuma diferença significativa foi encontrada entre as variáveis analisadas para os grupos S→CT e S→C (p>0,05). Os resultados obtidos neste estudo permitem concluir que o US de baixa potência contribuiu na prevenção e reversão da ocorrência da osteopenia nos animais submetidos à suspensão pela cauda, demonstrando que a ausência do estímulo mecânico causada pela impossibilidade da deambulação pode ser minimizada pela ação mecânica deste.

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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The aim of this work was to evaluate the performance and the liver structure health of Nile tilapia hormonally masculinized or nonmasculinized, reared in cages with two protein levels. Two groups of Nile tilapia of Thai lineage (total 2,400), with 127 g initial average weight, were distributed in a completely randomized design with four treatments, in a 2x2 factorial arrangement, corresponding to the groups of hormonally masculinized or nonmasculinized fish, and to diet protein level of 28 or 32% of crude protein, with three replicates. After 115 days feeding, there was no interaction between the factors for final weight, weight gain, feed conversion rate, final length and survival. There was no difference between hormonally masculinized and nonmasculinized fish for final weight, weight gain, and survival, which shows the possibility of their production in cages, without the need of hormonal masculinization. Crude protein at 32% in the diet enables a better performance for both groups. Histological changes in the liver - such as increased cell volume, disruption of the cord-like arrangements, and increase of vesicles in the hepatocytes - are found in hormonally masculinized fish, and are more pronounced in fish fed 32% crude protein in the diet.

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Pós-graduação em Aquicultura - FCAV

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This study presents the first results from Brazil using SF6 tracer technique adapted from cattle to evaluate the capability of condensed tannin (CT) present in three tropical legume forages, Leucaena leucocephala (LEU), Styzolobium aterrimum (STA), and Mimosa caesalpiniaefolia Benth (MIM) to reduce enteric CH4 production in Santa Ins sheep. Twelve male lambs [27.88 +/- 2.85 kg body weight (BW)] were allocated in individual metabolic cages for 20-day adaptation followed by 6 days for measuring dry matter intake (DMI) and CH4 emission. All lambs received water, mineral supplement, and Cynodon dactylon v. coast-cross hay ad libitum. The treatments consisted of soybean meal (710 g/kg) and ground corn (290 g/kg) [control (CON)]; soybean meal (150 g/kg), ground corn (30 g/kg), and Leucaena hay (820 g/kg) (LEU); soybean meal (160 g/kg), ground corn (150 g/kg), and Mucuna hay (690 g/kg) (STA); and soybean meal (280 g/kg), ground corn (190 g/kg), and Mimosa hay (530 g/kg) (MIM); all calculated to provide 40 g/kg CT (except for CON). DMI (in grams of DMI per kilogram BW per day) was lower for LEU (22.0) than CON (29.3), STA (31.2), and MIM (31.6). The LEU group showed emission of 7.8 g CH4/day, significantly lower than CON (10.5 g CH4/day), STA (10.4 g CH4/day), and MIM (11.3 g CH4/day). However, when the CH4 emission per DMI was considered, there were no significant differences among treatments (0.37, 0.36, 0.33, and 0.35 g CH4/g DMI/kg BW/day, respectively, for CON, LEU, STA, and MIM). The sheep receiving STA had shown a tendency (p = 0.15) to reduce methane emission when compared to the CON group. Therefore, it is suggested that tropical tanniniferous legumes may have potential to reduce CH4 emission in sheep, but more research is warranted to confirm these results.

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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The research aimed to estimate body contents of protein and energy and net requirements of energy for maintenance of buffaloes, slaughtered at different stages of maturity. There were used 14 Mediterranean intact males with initial average body weight of 352.2 +/- 24.3 kg and average age of 24 months. The animais were randomly divided into four experimental groups. One group was designed to slaughter at the beginning of the experimental period (IS). The animals of another group were restricting fed, receiving, individually, levels of protein and energy 15% above maintenance (RF). The animals of the two remaining groups were individually fed ad libitum (SW450 and SW500) to reach weights corresponding to 100 and 110 percent of the mature weight of the buffalo cows (respectively 450 and 550 kg). The ration contained ground-corn cobs, soybean meal, urea, minerals, and signal-grass (Brachiaria decumbens) hay, with a concentrate: roughage ratio of 50: 50 and 13% of crude protein on a dry matter basis. To estimate changes in body composition inside the range of weights included in the trial, linear regression equations of log protein (kg), fat (kg) and energy (Mcal) as a function of log empty-body-weight (EBW), in kg, were fitted. Energy requirements for maintenance were obtained as estimated heat production at zero level of energy intake. Buffaloes submitted to fattening in feedlot presented early body fat deposition, and had with the same live weight lower protein content and higher fat content and energy per unit weight than european-zebu crossbred cattle.

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Pós-graduação em Zootecnia - FMVZ

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)