Effects of dietary soy isoflavones on estrogenic activity,cortisol level,health and growth in rainbow trout,Oncorhynchus mykiss          下载免费PDF全文

Maria Rita Pastore  Elena Negrato  Carlo Poltronieri  Giuseppe Barion  Maria Messina  Francesca Tulli  Cristina Ballarin  Lisa Maccatrozzo  Giuseppe Radaelli  Daniela Bertotto 《Aquaculture Research》2018,49(4):1469-1479

Soy isoflavones (the phytoestrogens genistein, daidzein and glycitein) may act as estrogen receptor agonists or antagonists. The aim of this study was to examine the effect of dietary isoflavones on growth, reproduction and health in rainbow trout (Oncorhynchus mykiss). Rainbow trout fed three experimental diets containing different concentrations of isoflavones (0, 500 and 1,500 ppm). Growth, estrogenic activity, plasma estradiol levels, gonadal development, state of stress and histological changes in selected tissues were evaluated at the end of 70 days. Neither growth performance nor the relative mRNA levels of Insulin Growth Factor I (igf‐I) in the liver were influenced by different levels of dietary isoflavones. Plasma and liver vitellogenin (VTG) protein levels and plasma 17‐β‐estradiol (E₂) were unaffected by treatments, although the correlation between plasma levels of E₂ and VTG densitometry values was significant (p < .05). The fish gonadosomatic index (GSI) did not significantly differ among the three experimental groups but correlated with plasma VTG densitometry values (p < .05). Plasma, muscle and fin cortisol concentrations fell within the normal welfare range and were not correlated with isoflavone levels. Histologically, the distal intestine showed a normal morphology with well‐differentiated enterocytes and in the liver hepatocytes were also normal. A supranuclear accumulation of lipid droplets in enterocytes and some lipid droplets in hepatocytes were observed in all tested groups, suggesting an impact of basal dietary lipid on transport/metabolism of fat in the fish. Overall, the present results suggest that the doses of isoflavones tested do not compromise rainbow trout reproduction, growth and health.  相似文献   

Clinical West Nile virus infection in 2 horses in western Canada          下载免费PDF全文

Abutarbush SM  O'Connor BP  Clark C  Sampieri F  Naylor JM 《The Canadian veterinary journal. La revue veterinaire canadienne》2004,45(4):315-317

Two horses had a history of ataxia and weakness or recumbency. One recovered and was diagnosed with West Nile virus (WNV) infection by serologic testing. The other was euthanized; it had meningoencephalomyelitis, WNV was detected by polymerase chain reaction. West Nile virus infection is an emerging disease. Year 2002 is the first year in which cases have been seen in Saskatchewan.  相似文献   

Soil microbiome biomass,activity, composition and CO2 emissions in a long-term organic and conventional farming systems     

Margherita Santoni  Leonardo Verdi  Shamina Imran Pathan  Marco Napoli  Anna Dalla Marta  Francesca Romana Dani  Gaio Cesare Pacini  Maria Teresa Ceccherini 《Soil Use and Management》2023,39(1):588-605

The implementation of environmentally friendly agricultural policies has increased the need to compare agricultural aspects of conventional (CON) and organic farming (ORG) systems. The objective of the present work was to compare the effects of an organic and conventional long-term experiment on bacterial and fungal biomass and activity, as well as soil CO₂ emission and readily available nitrogen forms in a soil cultivated with Helianthus annuus L. The microbial biomass was more active and abundant in ORG as well as soil CO₂ emission. Despite being less abundant, fungi were more active than bacteria in both ORG and CON experiments. 16S rRNA gene sequencing showed that the ORG treatment had a significantly greater bacterial richness than CON. Cyanobacteria, Actinobacteria and Proteobacteria were the most abundant phyla contributing more than others to the differences between the two systems. Moreover, the soil ${\mathit{NH}}_4^{+}$ and ${\mathit{NO}}_2^{-}$ content was not significantly different between ORG and CON, while ${\mathit{NO}}_3^{-}$ was less in ORG. ORG sunflower yield was significantly less compared with CON. While much remains to be discovered about the effects of these agricultural practices on soil chemical properties and microbial diversity, our findings may contribute to this type of investigation.  相似文献