Digestibilidade aparente do farelo de palmiste em tambaqui (Colossoma macropomum) / Apparent digestibility of palm kernel meal to tambaqui (Colossoma macropomum)

O objetivo deste trabalho foi determinar a digestibilidade do farelo de palmiste (Elaeis guineensis) para o tambaqui (Colossoma macropomum), em duas classes de peso: 1 (210 alevinos de 4,45±1,18g) e 2 (54 juvenis de 115,91±4,01g). Os coeficientes de digestibilidade aparente (CDA) da matéria seca, proteína bruta e energia bruta do farelo de palmiste foram avaliados pela metodologia de substituição da dieta referência, utilizando-se 0,1% de óxido crômico como indicador externo. Os dados foram analisados pelo teste t de Student, a 5% de probabilidade. Os CDAs da matéria seca, proteína bruta e energia bruta do ingrediente foram iguais (P>0,05) nas classes de peso avaliadas. Os CDAs observados nas classes 1 e 2, respectivamente, foram: matéria seca (17,52% e 20,75%), proteína bruta (62,83% e 63,75%) e energia bruta (14,16% e 22,43%). A capacidade do tambaqui para digerir os nutrientes do farelo de palmiste não foi influenciada pelo peso corporal, e o aproveitamento satisfatório da proteína (63,29%) faz desse ingrediente uma potencial fonte alternativa de proteína em dietas para a espécie.(AU)

The objective of this work was to determine the digestibility of palm kernel meal (Elaeis guineensis) in tambaqui (Colossoma macropomum), in two weight classes: 1 (210 fingerlings of 4.45±1.18g) and 2 (54 juveniles of 115.91±4.01g). The apparent digestibility coefficients (ADC) of dry matter, crude protein and crude energy of the palm kernel meal were evaluated by the substitution of the reference diet methodology, using 0.1% chromic oxide as an external indicator. Data were analyzed by Student's t-test at 5% probability. The dry matter, crude protein and crude energy ADCs of the ingredient were the same (P> 0.05) in the weight classes evaluated. The ADCs observed in classes 1 and 2, respectively, were: dry matter (17.52% and 20.75%), crude protein (62.83% and 63.75%) and crude energy (14.16% and 22.43%). The ability of tambaqui to digest the nutrients of palm kernel meal was not influenced by body weight, and satisfactory protein utilization (63.29%) makes this ingredient a potential alternative source of protein in diets for the species.(AU)

LC-MS/MS quantitation of plasma progesterone in cattle.

Quantitation of progesterone (P(4)) in biological fluids is often performed by radioimmunoassay (RIA), whereas liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS) has been used much less often. Due to its autoconfirmatory nature, LC-MS/MS greatly minimizes false positives and interference. Herein we report and compare with RIA an optimized LC-MS/MS method for rapid, efficient, and cost-effective quantitation of P(4) in plasma of cattle with no sample derivatization. The quantitation of plasma P(4) released from three nonbiodegradable, commercial, intravaginal P(4)-releasing devices (IPRD) over 192 h in six ovariectomized cows was compared in a pairwise study as a test case. Both techniques showed similar P(4) kinetics (P > 0.05) whereas results of P(4) quantitation by RIA were consistently higher compared with LC-MS/MS (P < 0.05) due to interference and matrix effects. The LC-MS/MS method was validated according to the recommended analytical standards and displayed P(4) limits of detection (LOD) and quantitation (LOQ) of 0.08 and a 0.25 ng/mL, respectively. The high selective LC-MS/MS method proposed herein for P(4) quantitation eliminates the risks associated with radioactive handling; it also requires no sample derivatization, which is a common requirement for LC-MS/MS quantitation of steroid hormones. Its application to multisteroid assays is also viable, and it is envisaged that it may provide a gold standard technique for hormone quantitation in animal reproductive science studies.

Diesel emissions significantly influence composition and mutagenicity of ambient particles: a case study in São Paulo, Brazil.

In 2003, a bus strike paralyzed the fleet of buses in Sao Paulo, Brazil during 3 days, from 6 to 8 of April, the complete interruption of services being achieved on the 7th. We evaluated the effect of the absence of this source of pollution on the composition, mutagenicity, and toxicity of the fine particulate material collected during this period. Particles were sampled in glass fiber filters on days 7 and 15 of April of 2003 (strike and nonstrike days, respectively), using a high-volume sampler. Trace element determinations (As, Br, Co, Cl, Fe, La, Mn, Sb, Sc, and Th) of particulate material samples were carried out by neutron activation analysis. Sulfur determination was done by X-ray fluorescence analysis. The ratio between nonstrike/strike concentrations of hydrocarbons associated with automotive emissions (benzene, toluene, ethyl-benzene, and xylenes; BTEX) was determined by gas chromatography/mass spectrometry. Mutagenesis of testing solutions was determined by means of the Tradescantia micronucleus assay in early tetrads of Tradescantia pallida. The inhibition of mitosis of the cells of the primary meristema of the root tips of Allium cepa was used as an index of the toxicity. Fine particle trace element contents were lower during the strike. The concentrations of sulfur and BTEX were 50% and 39.3% lower, respectively, on the strike day. A significant (P=0.038) reduction of micronuclei induced by fine particles sampled during the strike was observed. No effect of the strike on toxicity was detected. These results indicate that a program aiming to reduce emissions of the bus fleet in our town may impact positively the air quality by reducing the mutagenic potential of ambient particles.

Astyanax fasciatus as bioindicator of water pollution of Rio dos Sinos, RS, Brazil

The effects of an increasing downriver pollution gradient on the reproductive system of Astyanax fasciatus were investigated in the Rio dos Sinos, RS. The comparison of mean oocyte diameters, gonadal indices and gonado-somatic relationships of specimens captured in polluted areas with individuals from unpolluted reference sites revealed a significant decrease of these parameters with increasing water pollution. High loads of organic and industrial sewage are considered responsible for these effects. Condition factors showed an inverse relationship, and increased significantly in downriver polluted areas. The declining gonadal indices showed that energy was allocated to somatic growth. The results of the study recommend the use of A. fasciatus in biomonitoring essays.

Os efeitos da crescente poluição ao longo do rio sobre o sistema reprodutivo de Astyanax fasciatus foram investigados no Rio dos Sinos, RS. A comparação dos diâmetros médios de ovócitos, do índice gonadal e da relação gônado-somática de espécimes capturadas em áreas poluídas com os indivíduos de locais sem poluição (área de referência) revelou diminuição significativa desses parâmetros com a crescente poluição da água. As cargas elevadas dos esgotos orgânicos e industriais são consideradas responsáveis por esses efeitos. Os fatores de condição mostraram relacionamento inverso e aumentaram significativamente nas áreas poluídas ao longo do rio. A diminuição dos índices gonadais mostrou que a energia é alocada no crescimento somático. Os resultados do estudo recomendam o uso de A. fasciatus em experiências de biomonitoramento.

Astyanax fasciatus as bioindicator of water pollution of Rio dos Sinos, RS, Brazil

The effects of an increasing downriver pollution gradient on the reproductive system of Astyanax fasciatus were investigated in the Rio dos Sinos, RS. The comparison of mean oocyte diameters, gonadal indices and gonado-somatic relationships of specimens captured in polluted areas with individuals from unpolluted reference sites revealed a significant decrease of these parameters with increasing water pollution. High loads of organic and industrial sewage are considered responsible for these effects. Condition factors showed an inverse relationship, and increased significantly in downriver polluted areas. The declining gonadal indices showed that energy was allocated to somatic growth. The results of the study recommend the use of A. fasciatus in biomonitoring essays

Astyanax fasciatus as bioindicator of water pollution of Rio dos Sinos, RS, Brazil.

The effects of an increasing downriver pollution gradient on the reproductive system of Astyanax fasciatus were investigated in the Rio dos Sinos, RS. The comparison of mean oocyte diameters, gonadal indices and gonado-somatic relationships of specimens captured in polluted areas with individuals from unpolluted reference sites revealed a significant decrease of these parameters with increasing water pollution. High loads of organic and industrial sewage are considered responsible for these effects. Condition factors showed an inverse relationship, and increased significantly in down-river polluted areas. The declining gonadal indices showed that energy was allocated to somatic growth. The results of the study recommend the use of A. fasciatus in biomonitoring essays.