87 research outputs found
Effect of age of Japanese quail on physical and biochemical characteristics of eggs
The aim of the study was to investigate the effects of age of birds on egg quality in Japanese quail. The eggs were randomly selected from among all eggs laid on the same day when the birds were 15, 23 and 31 weeks old. At each time point, 90 fresh eggs were evaluated for their physical and biochemical characteristics. Egg weights were similar over time. At 23 and 31 weeks, the eggs had less shell than at 15 weeks. Crude fat and ash contents of the eggs increased with the age of the birds. Crude protein was also highest in eggs of the oldest quail. At 31 weeks old, the eggs were lowest in pH of yolk and white. Quail that were 23 and 31 weeks old laid eggs with significantly higher polyunsaturated fatty acid (PUFA) and lower saturated fatty acid (SFA) contents. The lowest cholesterol content was in egg yolks from 23-week-old quail. The oldest birds had the highest contents of sodium, potassium, zinc, selenium, copper, and manganese. The content and activity of lysozyme decreased with ageing of the birds. From the consumersâ point of view, eggs from older birds appeared to be the most valuable. At the same time, as the quail ages, the antibacterial properties of eggs deteriorate, which may indicate a shorter shelf life
Insights into the abundance and diversity of abyssal megafauna in a polymetallic-nodule region in the eastern Clarion-Clipperton Zone
There is growing interest in mining polymetallic nodules in the abyssal Clarion-Clipperton Zone (CCZ) in the Pacific. Nonetheless, benthic communities in this region remain poorly known. The ABYSSLINE Project is conducting benthic biological baseline surveys for the UK Seabed Resources Ltd. exploration contract area (UK-1) in the CCZ. Using a Remotely Operated Vehicle, we surveyed megafauna at four sites within a 900âkm2 stratum in the UK-1 contract area, and at a site ~250âkm east of the UK-1 area, allowing us to make the first estimates of abundance and diversity. We distinguished 170 morphotypes within the UK-1 contract area but species-richness estimators suggest this could be as high as 229. Megafaunal abundance averaged 1.48âind. mâ2. Seven of 12 collected metazoan species were new to science, and four belonged to new genera. Approximately half of the morphotypes occurred only on polymetallic nodules. There were weak, but statistically significant, positive correlations between megafaunal and nodule abundance. Eastern-CCZ megafaunal diversity is high relative to two abyssal datasets from other regions, however comparisons with CCZ and DISCOL datasets are problematic given the lack of standardised methods and taxonomy. We postulate that CCZ megafaunal diversity is driven in part by habitat heterogeneity.This open access work is licensed under a Creative Commons Attribution 4.0 International License. The images
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Status of Biodiversity in the Baltic Sea
The brackish Baltic Sea hosts species of various origins and environmental tolerances. These immigrated to the sea 10,000 to 15,000 years ago or have been introduced to the area over the relatively recent history of the system. The Baltic Sea has only one known endemic species. While information on some abiotic parameters extends back as long as five centuries and first quantitative snapshot data on biota (on exploited fish populations) originate generally from the same time, international coordination of research began in the early twentieth century. Continuous, annual Baltic Sea-wide long-term datasets on several organism groups (plankton, benthos, fish) are generally available since the mid-1950s. Based on a variety of available data sources (published papers, reports, grey literature, unpublished data), the Baltic Sea, incl. Kattegat, hosts altogether at least 6,065 species, including at least 1,700 phytoplankton, 442 phytobenthos, at least 1,199 zooplankton, at least 569 meiozoobenthos, 1,476 macrozoobenthos, at least 380 vertebrate parasites, about 200 fish, 3 seal, and 83 bird species. In general, but not in all organism groups, high sub-regional total species richness is associated with elevated salinity. Although in comparison with fully marine areas the Baltic Sea supports fewer species, several facets of the system's diversity remain underexplored to this day, such as micro-organisms, foraminiferans, meiobenthos and parasites. In the future, climate change and its interactions with multiple anthropogenic forcings are likely to have major impacts on the Baltic biodiversity
Is the meiofauna a good indicator for climate change and anthropogenic impacts?
Our planet is changing, and one of the most pressing challenges facing the scientific community revolves around understanding how ecological communities respond to global changes. From coastal to deep-sea ecosystems, ecologists are exploring new areas of research to find model organisms that help predict the future of life on our planet. Among the different categories of organisms, meiofauna offer several advantages for the study of marine benthic ecosystems. This paper reviews the advances in the study of meiofauna with regard to climate change and anthropogenic impacts. Four taxonomic groups are valuable for predicting global changes: foraminifers (especially calcareous forms), nematodes, copepods and ostracods. Environmental variables are fundamental in the interpretation of meiofaunal patterns and multistressor experiments are more informative than single stressor ones, revealing complex ecological and biological interactions. Global change has a general negative effect on meiofauna, with important consequences on benthic food webs. However, some meiofaunal species can be favoured by the extreme conditions induced by global change, as they can exhibit remarkable physiological adaptations. This review highlights the need to incorporate studies on taxonomy, genetics and function of meiofaunal taxa into global change impact research
Meiobenthic communities of the Szczecin Lagoon
Based on data collected at 7 stations 4 times a year in 1985 and 1986, composition and distribution of meiobenthic communities in the Polish part of the Szczecin Lagoon, a eutrophic and polluted water body connected with the Baltic Sea, is presented. The data show a tendency to reduced total meiobenthos densities and diversity from the lower to upper reaches of the lagoon. The meiobenthic communities studied were dominated by nematodes, ostracods ranking second in numerical importance. Harpacticoid copepods were most abundant at the outer stations which are influenced by Baltic inflows. Most of the 10 harpacticoid species recorded in the lagoon were found at the outer stations (lower reaches) as well. Similarity analysis allowed to separate three zones within the lagoon: (1) the outer zone, its stations showing most abundant and diverse meiobenthic communities; (2) the innermost zone (upper reaches) with the least abundant and qualitatively impoverished communities; and (3) the intermediate zone
Microflora and mycotoxin contamination in poultry feed mixtures from western Poland
Objective: Contamination of feeds with pathogenic microflora and mycotoxins constitutes a serious threat both for animals
and humans. The aim of the study was to determine the degree of risk of the occurrence of microscopic fungi, selected
bacteria and mycotoxins from the trichothecene group in poultry feeds in western Poland.
Results: In feed mixtures, the concentration of ergosterol (ERG), being a specific quantitative biomarker for the content of
microscopic fungi, was determined. Grower and finisher feeds were characterized by a higher count of bacteria and fungi
in comparison to starter feeds. A considerable variation was found in the amount of ergosterol in analyzed feeds. Mean
ergosterol content in feeds amounted to 19.34 mg/kg. The most common genera of fungi detected in the tested feeds
included Aspergillus, Rhizopus and Mucor. Irrespective of the type of feed, the proportion of trichothecenes group B was five
times higher than that of trichothecenes group A in relation to the total content of these mycotoxins in samples. In terms
of the analyzed mycotoxins, feeds contained the highest concentration of deoxynivalenol (DON). A statistically significant
correlation was shown between DON and ERG and between total trichothecenes and ERG.
Conclusion: Recorded results indicate that the level of microbiological contamination in feeds for broiler chickens produced
in western Poland is within the requirements of the binding standards
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