Atlantic salmon, Salmo salar, utilizes wax ester-rich oil from Calanus finmarchicus effectively

Against a background of decreasing availability of fish oils for use in aquaculture, the present study was undertaken to examine whether a wax ester-rich oil derived from the calanoid copepod Calanus finmarchicus, could be used effectively by Atlantic salmon when supplied in their diet. Individually tagged Atlantic salmon of initial weight around 500 g were divided into replicate tanks of two dietary groups and fed either a fish oil supplemented diet, or an experimental diet coated with Calanus oil. Wax esters accounted for 37.5% of the lipids in the Calanus oil diet but were absent from the fish oil diet in which triacylglycerols (TAG) were the major lipid class. Over the feeding period (140 days) the salmon fed fish oil displayed a greater increase in length, but there was no significant difference between the two groups in weight gained. The specific growth rates (0.75) and the feed conversion ratio of fish fed the two diets were similar throughout the study. No differences were observed in the apparent digestibility coefficients (ADC) of fish fed Calanus oil or fish oil. The ADC of fatty acids decreased with chain length and increased with unsaturation. Long-chain alcohol utilization showed a similar tendency although there was a notable difference in that saturated long-chain alcohols were utilized better than the comparable fatty acid homologue. In fecal lipid of fish fed Calanus oil, the content of 16:0 alcohol decreased in both the free long-chain alcohol and wax ester fractions, while the corresponding fatty acid increased in the feces of both dietary groups of fish. In contrast, the proportion of the 22:1n−11 alcohol increased in both fecal wax esters and free long-chain alcohol fractions whereas 22:1n−11 fatty acid displayed no accumulation. The observed patterns of fatty acid and long-chain alcohol compositions in fecal lipid compared to those of the initial dietary lipid are consistent with the digestive lipases of salmon preferentially hydrolyzing esters containing polyunsaturated fatty acid (PUFA) moieties. The wax esters of Calanus oil contained substantial amounts of the n−3 PUFA, 20:5n−3 and 22:6n−3, that were effectively deposited in muscle and liver tissues. No major differences were seen in either lipid content/lipid classes or in gross fatty acid composition of these tissues between the two dietary groups. It is concluded that that Atlantic salmon in seawater can effectively utilize diets in which a major lipid component is derived from zooplankton rich in wax ester without any detrimental change in growth or body lipid composition. This finding gives support to the use of lipid from zooplankton from high latitudes as an alternative or as a supplement to fish oil and a provider of long-chain n−3 PUFA in diets for use in salmon aquaculture.     

Teton Russet: An Early-Maturing,Dual-Purpose Potato Cultivar Having Higher Protein and Vitamin C Content,Low Asparagine,and Resistances to Common Scab and Fusarium Dry Rot

Teton Russet is an early-maturing, medium-russeted, potato cultivar with high merit for both fresh-pack and processing. In early harvest trials in the Pacific Northwest, Teton Russet had total yields similar to Russet Norkotah, and higher than Ranger Russet and Russet Burbank. Marketable yield of Teton Russet in the early harvest trials was also comparable to or higher than Russet Norkotah in Washington and Oregon, and higher than Ranger Russet and Russet Burbank at these sites, as well as in Idaho. In full-season trials, while total yield of the earlier-maturing Teton Russet tended to be lower than Ranger Russet and Russet Burbank, marketable yield was generally higher than Russet Burbank across the majority of sites due to its higher percentage of U.S. No. 1 tubers. Teton Russet is suitable for processing, with acceptable fry color following up to 8 months of storage at 8.9 °C. Uniformity of fry color was also very consistent. Teton Russet has shown lower levels of the amino acid asparagine relative to Ranger Russet and Russet Burbank which may contribute to lower acrylamide levels in French fries and other processed potato products. Teton Russet is notable for having resistance to common scab (Streptomyces spp.) and Fusarium dry rot, and is moderately resistant to tuber net necrosis. Analyses have also shown Teton Russet to have significantly higher protein levels than Russet Norkotah, Ranger Russet, and Russet Burbank, as well as higher vitamin C content than Russet Norkotah and Russet Burbank. Teton Russet was released in 2011 by the USDA-ARS and the Agricultural Experiment Stations of Idaho, Oregon, and Washington, and is a product of the Pacific Northwest Potato Variety (Tri-State) Development Program.     

Ash and biochar amendment of coarse sandy soil for growing crops under drought conditions

Appropriate soil amendments may increase plant available water and crop yields on coarse sandy soils under drought conditions. In this study, we applied straw ash or straw biochar from gasification to a Danish coarse sandy subsoil to assess the effects on soil water retention, evapotranspiration and crop yields. Spring barley (2016, 2017) and winter wheat (2018) were grown over three years in columns containing 25cm of organic matter-rich topsoil, 80 cm of amended coarse sandy soil (1.5%, 3%, 6% wt. ash or 1% wt. biochar or control soil) and 45 cm of un-amended subsoil. Precipitation, evaporative demands and soil moisture were recorded across the growth seasons, with 2018 having severe drought conditions. This year evapotranspiration levels increased with increasing ash and biochar content (by 54% and 33% for the 6% ash- and 1% biochar-amended soils, respectively), and plant dry matter increased by 18% in both the 1% biochar- and 6% ash-treated soils compared to the untreated control. A linear relationship was established between in situ field capacity and ash dosage (R² = .96), showing an increase of 2.2% per percentage (wt.) of ash added, while the 1% biochar treatment increased the capacity by 3.5%, indicating a higher efficiency than for ash. However, we did not find significant positive effects on grain yields. The results show that ash and biochar have the potential to significantly increase soil water retention, evapotranspiration and total dry matter yield in drought conditions, but that this may not correspond to an increase in grain yield.     

Fatty acid composition of 12 microalgae for possible use in aquaculture feed

Twelve algal strains representing the classes Cyanophyceae, Prymnesiophyceae, Bacillariophyceae, Rhodophyceae, Cryptophyceae, Chlorophyceae, Xantophyceae and Eustigmatophyceae were selected mainly from the culture collection of the Norwegian Institute for Water Research (NIVA). The algae were grown as continuous cultures in a 1.8 l. reactor, internally illuminated with an 11 W fluorescent tube. The retention time was adjusted in the range 2–4 days to fit the growth rate of the algae. The growth responses and fatty acid composition were analysed. The maximum production rate was obtained with Pseudokirchneriella subcapitata (0.63 g 1⁻¹ day⁻¹) and the lowest with Porphyridium cruentum 0.13 g 1⁻¹ day⁻¹. Arachidonic acid (AA) and eicosapentaenoic acid (EPA) were the dominating polyunsaturated fatty acids (PUFAs) in P. cruentum, while only EPA accumulated in Phaeodactylum tricornutum. Docosahexaenoic acid (DHA) was the major PUFA in Isochrysis galbana, while Pavlova sp. had both EPA and DHA. This is the first report on the fatty acid profiles of Nannochloropsis oceanica, Chroococcus sp., Synechococcus sp. and Tribonema sp.     

Evaluation of the Brucella abortus species-specific polymerase chain reaction assay, an improved version of the Brucella AMOS polymerase chain reaction assay for cattle.

In a blind test, 344 samples representing 80 bacterial isolates were analyzed by the Brucella abortus species-specific polymerase chain reaction (BaSS PCR) assay for the identification and discrimination of B. abortus field strains (wild-type biovars 1, 2, and 4) from 1) B. abortus vaccine strains, 2) other Brucella species, and 3) non-Brucella bacteria. Identical samples were tested in 2 laboratories. Half the samples were fully viable, and half were bacteria that had been killed by methanol fixation. The results in 1 laboratory correctly identified 100% of the samples, resulting in a predictive value of 100% for all categories and 100% sensitivity and specificity under the prescribed conditions. The second laboratory misidentified 31 samples, resulting in a range of 66.7-100% sensitivity, 93.2-99.7% specificity, and 77.3-98.2% predictive values depending on the category. There was no significant difference in viable versus fixed bacteria for either laboratory. Subsequent review of the protocol indicated that contamination was the likely cause of 26 of the 31 erroneous identifications. The results show that the BaSS PCR assay has the potential to be a very reliable screening tool for B. abortus identification. However, the data also provide a cautionary reminder of the importance of preventing contamination in diagnostic PCR.     

Determination of the oxidative burst chemiluminescent response of avian and murine-derived macrophages versus corresponding cell lines in relation to stimulation with Salmonella serotypes.

In contrast to mammalian systems, avian species lack a resident or harvestable macrophage population in the abdominal exudate. Peritoneal macrophages in the chicken can be elicited if an inflammatory agent such as sephadex is injected. This study examines the kinetics of different macrophage populations, derived by different methods of isolation and from different hosts, with respect to the elicited oxidative burst upon infection with host-adapted Salmonella serotypes.

The nature of the oxidative burst elicited by murine and avian-derived and cell line macrophages was determined after stimulation with phorbol myristate (PMA), zymosan A, and Salmonella serotypes. Both murine and chicken peritoneal macrophages, chicken blood monocytes and corresponding cell lines, J774A.1 and HD-11, were unable to produce a detectable chemiluminescent (CL) response after interaction with Salmonella using the luminescent probe luminol. However, both PMA and zymosan A induced a CL response in all cell types, with PMA eliciting a higher and earlier peak response (pkH) than zymosan A. Lucigenin-enhanced CL in both murine and chicken macrophages was achieved with PMA, zymosan A and Salmonella serotypes. In this case, zymosan A induced higher responses than PMA. In the peritoneal macrophages of both hosts, there were no significant differences in the oxidative burst induced by the different Salmonella serotypes. However, the J774A.1 (murine) cells demonstrated significant differences, with S. enterica serotype Choleraesuis (S. choleraesuis and S. gallinarum producing the highest response. In the HD-11 (chicken) cells, S. choleraesuis and S. dublin elicited the higher CL. With both cell lines, S. abortusovis failed to induce an appreciable CL response.

In these experiments it was demonstrated that oxidative burst was not detectable in monocytes/macrophage populations using luminol, which suggests a link to the lack of a myeloperoxidase system in these cells. Lucigenin-enhanced CL appeared independent from the myeloperoxidase system, indicating production of another oxidative species compared with luminol. No discernable effect of host specificity with regard to Salmonella serotype and respective host was seen in host-derived or cell line macrophages, and cell line macrophages displayed altered functional characteristics with regard to oxidative burst in comparison with their primary counterparts.     

Genetic basis of grain filling rate in wheat (Triticum aestivum L. emend. Thell.)

Summary Grain filling rate in wheat (Triticum aestivum L. emend. Thell.) positively influences grain yield under a wide range of conditions. The effective utilization of this trait in breeding depends on an understanding of its genetic control. A study was, therefore, conducted to determine the genetic basis of grain filling rate in six crosses of wheat. Higher order genic interactions and/or linkage were important in the genetic regulation of grain filling rate (GFR) in the majority of crosses. Additive ([d]) and dominance ([h]) gene effects were important in the control of GFR in main ears (ME) and whole plant ears (WPE). Additive and additive × additive epistatic effects were the most important in the genetic control of GFR in last ears (LE). Location effects on genetic effects for GFR were significant (P < 0.05) in all ear types of some crosses except in ME. Genotype × environment interaction effects were important (P < 0.001) in LE and WPE.It was concluded that the inheritance of GFR is complex and is dependent on ear type. Breeding procedures that facilitate the exploitation of non-additive and additive gene effects were recommended for the genetic improvement of grain filling rate of wheat.     

Cyclic change in late triassic lacustrine communities

A new type of lake and shore assemblage has been found in the Late Triassic age rocks of North Carolina and Virginia (Dan River group). It includes abundant aquatic reptiles, fishes, at least seven orders of insects, crustaceans, and a diverse flora. Cyclic changes in the fauna and flora correlate with sedimentary cycles, which together reflect the repetitive development and extinction of large meromictic lakes.