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91.
The effects of supplemented protein level (PL) during the periconceptional period and their interaction with body condition were evaluated in sheep. Multiparous Rambouillet ewes (n = 12) received two PL of rumen undegradable protein (UIP) during a 30‐day pre‐mating and 15‐day post‐mating period: low [LPL, 24% crude protein (CP), 14 g UIP and 36 g/CP animal/day] and high [HPL, 44% CP, 30 g UIP and 50 g/CP animal/day]. While ovulation rate (OR) did not differ between treatments (1.6 ± 0.5, mean ± SEM), a lower fertility rate, a decreased embryo number and a reduced uterine pH (UpH) was observed in the HPL group (p < 0.05), irrespective of BC. Luteal tissue weight, volume and progesterone secretion did not differ among treatments. Sheep with lower UpH also had lower conceptus weight (Cwt; p < 0.05, r = 0.65) and conceptuses with lower mass tended to secrete less INF‐τ and IGF‐1, and the correspondent endometrial explants had a higher basal PGF release. Current study indicates that high protein diets during the periconceptional period in sheep modify uterine and embryonic relationships, increasing early pregnancy losses and inducing embryo growth retardation. Surviving embryos were affected by weight reductions, which could compromise later foetal growth and birth weight. Results evidence the key role of a balanced diet in reproductive success and indicate that the quality and nutrient composition of the maternal diet are essential for an adequate establishment of pregnancy, having paramount effects on the interplay of the embryo and the uterus.  相似文献   
92.
Renibacterium salmoninarum is the causative agent of bacterial kidney disease, which significantly affects salmonid farming worldwide. Despite this impact, there is scarce data on its iron uptake ability, a factor of pathogenesis. This study investigated the iron acquisition mechanisms of R. salmoninarum and its capacity to uptake iron from different sources. Thirty‐two Chilean isolates and the DSM20767T type strain grew in the presence of 2,2′‐Dipyridyl at varying concentrations (250–330 μm ), and all isolates positively reacted on chrome azurol S agar. Subsequently, inocula of four Chilean isolates and the type strain were prepared with or without 200 μm of 2,2′‐Dipyridyl for uptake assays. Assay results revealed differences between the isolates in terms of iron acquisition. While a prior iron‐limited environment was, for most isolates, not required to activate the uptake of iron (II) sulphate, ammonium iron (III) citrate or iron (III) chloride at higher concentrations (100 μm ), it did facilitate growth at lower iron concentrations (10 μm and 1 μm ). An exception was the H‐2 isolate, which only grew with 100 μm of iron sulphide. In turn, 100 μm of haemin was toxic when isolates were grown in normal KDM‐2. In silico R. salmoninarumATCC 33209T genome analysis detected various genes coding iron uptake‐related proteins. This is the first study indicating two iron acquisition systems in R. salmoninarum: one involving siderophores and another involving haem group utilization. These data represent a first step towards fully elucidating this virulence factor in the pathogenic R. salmoninarum.  相似文献   
93.
The population structure and genetic variation of Tomato torrado virus (ToTV) were estimated from 19 Spanish isolates collected from 2001 to 2009 in different tomato‐production areas by analyses of the partial nucleotide sequences of five regions of the virus genome: the protease cofactor (Pro‐Co) and the RNA‐dependent RNA polymerase (RdRp) in RNA1, and the movement protein (MP) and two subunits of the coat protein (CP; viz. Vp35 and Vp23) in RNA2. Three Hungarian isolates of the virus were also included in the analyses. All the ToTV isolates clustered together in the phylogenetic analysis of the nucleotide sequences of the different regions. However, some genetic diversity was observed in the case of the two CP subunits among the Gran Canaria isolates and the remaining ToTV‐isolates analysed, which grouped together. A high similarity was observed among all the isolates and the two published ToTV isolates: the ToTV type isolate (PRI‐ToTV0301) and the Polish isolate Wal03. The most variable encoding regions studied were those on RNA2. In general, no correlation was found between genetic diversity and collection date. Studying the genetic distances between pairs of sequences, the ratio between nonsynonymous (amino‐acid‐replacing) and synonymous (silent mutational) substitutions was low, indicating a strong negative selective pressure in the studied regions. Nine negatively selected sites (distributed in Pro‐Co, MP, Vp23 and Vp35) and just one positively selected one (in Pro‐Co) were found for all the genome regions studied.  相似文献   
94.
This paper studies fire severity through changes in the composition of the 1:5 soil: water extract in burnt and unburnt samples collected after a wildfire that affected 7.1 ha of mountainous broom scrub (Teide broom, Spartocytisus supranubius L.) in Tenerife (Canary Islands). Soil samples were collected over a regular sampling grid and analysed for pH, electrical conductivity (E.C.), and soluble cations (Ca+2, Mg+2, K+, and NH4+–N) and anions (P, SO4− 2–S, and NO3?N). A visual estimation of fire effects on individual broom plants was also conducted. The results show significant differences between burnt and unburnt samples for pH, E.C. and soluble ions (except for P), which generally agrees with data reported in the literature. Although fire severity, as estimated from the degree of fuel combustion, correlated significantly with most of the studied parameters, the qualitative fire severity indexes failed to discriminate sample groups apparently exposed to moderate fire severity conditions. Multivariate statistical analysis (PCA) allowed extracting two main factors, capable to account for 88% of total variability, after rejecting three variables (inorganic N-forms and K+). These factors were related to fire severity and pH-dependent Ca+2 and P reactions, respectively.  相似文献   
95.
96.
In this work, we have assessed the effects of different stocking densities on the biometry, survival and physiological status of the wedge sole (Dicologoglossa cuneata), focusing on changes in the stress system and intermediate metabolism, with the aim of determining a stress indicator for chronic‐stress situations in this species. Wedge sole were kept at three different stocking densities (0.2, 0.4 and 0.8 kg m?3) for 197 days, and survival, growth, plasma metabolites, cortisol and enzymatic activities were assessed. Survival rates were the highest at low density, though growth did not vary significantly among treatments. Enzymatic activities, mainly in muscle, differed depending on stocking density. Liver hexokinase activity at low stocking density was the highest, while no differences were detected for the other enzymes assessed. In muscle, all enzymes significantly increased in activity with stocking density. We concluded that long‐term high stocking density culture significantly changed enzyme activities (hexokinase, glutamate dehydrogenase, glyceraldehyde 3‐phosphate dehydrogenase, and lactate dehydrogenase) in wedge sole muscle, although liver enzymes, plasma cortisol and metabolites did not vary significantly. Therefore, muscle enzymes, hexokinase and glutamate dehydrogenase, could be considered stress indicators for this species in chronic‐stress situations.  相似文献   
97.
The effects of two diets with different lipid composition (squid Loligo gahi and one commercial pellet for breeders) on reproductive performance and egg lipid composition of brill (Scophthalmus rhombus) were compared. A total of 36 adult brill weighing 1482 ± 432 g were randomly distributed in the experimental tanks. A flow‐through system composed of four tanks with 4.2 m2 of bottom area (5.0 m3 × 1.2 m water depth) was used. The experiment lasted for approximately 5 months (168 days). From the four mature females fed squid, three ovulated. Five females fed pellets matured and ovulated. Total ovulations were of 10 and 44, by the three females fed squid and the five ovulating female fed pellets respectively. Egg viability was higher, although not significantly, for females fed pellets. This indicates that pellets could be a better food for breeding females. In general, the egg total lipid content and the lipid classes composition did not seem to be affected by diet. In contrast, results indicate that not only diets but also individual females, regardless of the diet consumed, are determinant for egg fatty acid composition, clearly modulating their composition.  相似文献   
98.
As with many species of seahorses, Hippocampus hippocampus wild populations are being subjected to uncontrolled exploitation in their natural environment. Thus, aquaculture could contribute to satisfy the commercial demand for animals while promoting the recovery of wild stocks. The present study was conducted to compare the effect of the substituting Artemia nauplii with rotifers for first feeding seahorse juveniles. Survival, growth and biochemical composition of prey organisms and fish were studied during the feeding trial. In addition, to help the biometric study, an anaesthetic test was also carried out using clove oil. The results showed excellent survival (average 60%) in juveniles exclusively fed with Artemia, with better values than those reported previously obtained by other authors for this species. By comparison, high mortality and poor growth were observed during first feeding with seahorses fed on rotifers. This could have been related to the lower energy intake and poorer nutritional value of the rotifers. Furthermore, clove oil concentrations of 25 ppm were found to work well as an anaesthetic for seahorse juveniles. Overall, first feeding Artemia alone was found to be an efficient and simplified method for feeding young H. hippocampus fry, building the principles for their culture for ornamental or re‐stocking purposes.  相似文献   
99.
Sheep were immunised with Corynebacterium pseudotuberculosis toxoid formulated as a monocomponent vaccine with aluminium adjuvant or in combination with 5 clostridial antigens, and also in the combined form with sodium selenate. Immunised and control sheep were experimentally infected 16 days after vaccination and slaughtered and inspected after a further 3 months to determine their resistance to infection. All 3 vaccines afforded an equal and high level of protection; 91% of vaccinated sheep exhibiting no lesions of caseous lymphadenitis compared with 51.5% affected sheep in the control group. Average lesion counts were 1.2 per affected vaccinated sheep and 4.5 per affected control sheep. Antitoxin responses to the clostridial toxoids incorporated in the combined vaccines were not affected by inclusion of the C pseudotuberculosis toxoid or the sodium selenate.  相似文献   
100.
The course of Trypanosoma evansi infection in coatis (Carnivora, Procionidae) was followed for 262 days. Parasites were detected in all infected animals from day 2 post infection until the end of the study. No correlation between temperature and parasitemia was observed. Animals of the infected group demonstrated depression, weakness, lethargy and pale mucous membranes. Indirect fluorescent antibody tests detected anti-T. evansi antibodies within 7 to 14 days post infection and showed high levels until the end of the experimental period. The persistent parasitemia in coati and their relative tolerance to clinical signs suggested that this species develops a chronic disease and plays an important role in the epidemiology of trypanosomosis due to T. evansi in enzootic regions.  相似文献   
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