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31.
It is useful to determine the gestational age in sheep to provide essential information for effective flock management practices. The aims of this study were to evaluate the efficacy and practical aspects for using two ultrasound techniques, transabdominal and transrectal, in determining the gestational age in Württemberg ewes. Monitoring of embryo and fetus developmental stages during the ewes’ gestation was carried out with real time ultrasound using a transabdominal convex probe, frequency 3.5 MHz, and a transrectal linear probe, frequency 7.5 MHz. The size of the embryonic vesicle during the period from the 23rd to the 38th day of gestation can be used as a confirmational indicator of gestational age when the transrectal probe is used. The occipital nasal diameter correlated with the gestational age with both transabdominal (P < 0.05) and transrectal probes (P < 0.01) from the 46th to the 63rd day of gestation. The biparietal diameter of the fetal head measured by transabdominal probe during the period from the 46th to the 63rd day of gestation correlates with gestation age (P < 0.05). The diameter of the fetal eye orbit monitored by transrectal probe from the 46th to the 63rd day of gestation also correlated well with gestational age (P < 0.05).  相似文献   
32.
Biological invasions are a major driver of global environmental change as invasive non-native species can exert severe environmental impacts on invaded ecosystems. Estuaries are especially vulnerable to biological invasions, which in highly urbanised areas are further facilitated by introduction pathways linked to commercial activities. This study provides a risk screening of non-native invasive species for the highly urbanised River Neretva Estuary (Eastern Adriatic Sea: Croatia and Bosnia–Herzegovina). In total, 12 species of non-native aquatic organisms were identified and screened for their invasiveness with the Aquatic Species Invasiveness Screening Kit. Of these species, eight were classified as carrying a high risk of invasiveness under current climate conditions and nine under future climate conditions. Amongst the high-risk species, blue crab Callinectes sapidus has already caused impacts in the risk assessment area, where it also represents an important economic resource. The “horizon” species Pacific oyster Crassostrea gigas and Manila clam Ruditapes philippinarum also carried a high risk of invasiveness, which for the latter species applied under predicted global warming. The present findings will contribute towards preventative management and control measures for the conservation of the natural ecosystem of the River Neretva Estuary whilst accounting for aquatic farming demands.  相似文献   
33.
Birdsfoot trefoil (Lotus corniculatus L.) is a highly variable and widely distributed Old World perennial forage legume found in wild and naturalized populations throughout temperate regions of Europe, Asia Minor, North Africa, North and South America, Australia, and New Zealand. Understanding the relationships among birdsfoot trefoil morphological, ecogeographic and chemical characteristics may provide insights for better utilizing of exotic germplasms. Ten birdsfoot trefoil populations were and sampled and determined in Serbia and Bosnia and Herzegovina. Some morphological properties, such as growth form of populations, flower color, flowering period, number of stems, length of main stem, number of racemes per stem, number of flowers per inflorescence, number of pods per racemes, number of seeds per pods, hard seeds in the first year, dry matter (DM) yield, and some chemical properties, such as content of crude protein, ash, fat, crude fiber, phosphorus, calcium, magnesium, potassium, K/(Ca+Mg) ratio, and sulfur, manganese, iron, copper, zinc, selenium and tannin contents, were determined in all populations. Serbia is an important origin center of genes for many legume species. Considering the high values of their traits, some Serbian trefoil populations could serve as a valuable breeding material. In comparison with populations from other parts of the world, Serbian populations are superior in chemical properties and nutritional quality values. The investigated populations clustered in two distinct groups according to the analyzed characteristics.  相似文献   
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