Association between the genetic similarity of the open reading frame 5 sequence of Porcine reproductive and respiratory syndrome virus and the similarity in clinical signs of Porcine reproductive and respiratory syndrome in Ontario swine herds

A study of Ontario swine farms positive for Porcine reproductive and respiratory syndrome virus (PRRSV) tested the association between genetic similarity of the virus and similarity of clinical signs reported by the herd owner. Herds were included if a positive result of polymerase chain reaction for PRRSV at the Animal Health Laboratory at the University of Guelph, Guelph, Ontario, was found between September 2004 and August 2007. Nucleotide-sequence similarity and clinical similarity, as determined from a telephone survey, were calculated for all pairs of herds. The Mantel test indicated that clinical similarity and sequence similarity were weakly correlated for most clinical signs. The generalized additive model indicated that virus homology with 2 vaccine viruses affected the association between sequence similarity and clinical similarity. When the data for herds with vaccine-like virus were removed from the dataset there was a significant association between virus similarity and similarity of the reported presence of abortion, stillbirth, preweaning mortality, and sow/boar mortality. Ownership similarity was also found to be associated with virus similarity and with similarity of the reported presence of sows being off-feed, nursery respiratory disease, nursery mortality, finisher respiratory disease, and finisher mortality. These results indicate that clinical signs of PRRS are associated with PRRSV genotype and that herd ownership is associated with both of these.     

Necrotizing Meningoencephalitis in Atypical Dog Breeds: A Case Series and Literature Review

Background

Canine necrotizing meningoencephalitis (NME) is a fatal, noninfectious inflammatory disease of unknown etiology. NME has been reported only in a small number of dog breeds, which has led to the presumption that it is a breed‐restricted disorder.

Hypothesis/Objectives

Our objective was to describe histopathologically confirmed NME in dog breeds in which the condition has not been reported previously and to provide preliminary evidence that NME affects a wider spectrum of dog breeds than previously reported.

Animals

Four dogs with NME.

Methods

Archives from 3 institutions and from 1 author''s (BS) collection were reviewed to identify histopathologically confirmed cases of NME in breeds in which the disease has not been reported previously. Age, sex, breed, survival from onset of clinical signs, and histopathologic findings were evaluated.

Results

Necrotizing meningoencephalitis was identified in 4 small dog breeds (Papillon, Shih Tzu, Coton de Tulear, and Brussels Griffon). Median age at clinical evaluation was 2.5 years. Histopathologic abnormalities included 2 or more of the following: lymphoplasmacytic or histiocytic meningoencephalitis or encephalitis, moderate‐to‐severe cerebrocortical necrosis, variable involvement of other anatomic locations within the brain (cerebellum, brainstem), and absence of detectable infectious agents.

Conclusions and Clinical Importance

Until now, NME has only been described in 5 small dog breeds. We document an additional 4 small breeds previously not shown to develop NME. Our cases further illustrate that NME is not a breed‐restricted disorder and should be considered in the differential diagnosis for dogs with signalment and clinical signs consistent with inflammatory brain disease.     

Effect of feeding level on growth and nutrient deposition in rainbow trout (Oncorhynchus mykiss Walbaum) growing from 150 to 600 g

The effects of feeding level on growth and energy partitioning were studied in rainbow trout growing from 150 to 600 g. Triplicate groups of fish (initial weight 158 g fish^?1) were fed a practical diet at various feeding levels (25%, 50%, 75% and 100% of near satiation) for 24 weeks at 8.5°C. The final body weights of fish were 235, 381, 526 and 621 g. Restricted feeding levels significantly reduced live weight gain. Feeding levels had less pronounced effects on feed efficiency ratio, which were 0.98, 1.08, 1.02 and 0.83, respectively, for the 25%, 50%, 75% and 100% feeding levels. The growth of fish fed to near satiation was accurately described by the thermal‐unit growth coefficient. The growth data also showed that the widely used specific growth rate was not an appropriate model. Fish fed at the lowest feeding level (25%), which represented a maintenance ration (energy gain was less than 2 kJ fish^?1 day^?1), showed positive protein deposition but negative lipid deposition. This indicates that fish fed a maintenance ration mobilize body lipid reserve to support protein deposition. The efficiency of energy for growth (k_g) was estimated to be 0.63. The factorial multiple regression approach estimated that the partial efficiencies of metabolizable energy utilization for protein deposition (k_p) and lipid deposition (k_f) were 0.63 and 0.72, and that maintenance energy requirement was about 19 kJ (kg BW^0.824)^?1, for rainbow trout held at 8.5°C.     

Development of a multiplex PCR assay to detect Edwardsiella tarda,Streptococcus parauberis,and Streptococcus iniae in olive flounder (Paralichthys olivaceus)

A multiplex PCR protocol was established to simultaneously detect major bacterial pathogens in olive flounder (Paralichthys olivaceus) including Edwardsiella (E.) tarda, Streptococcus (S.) parauberis, and S. iniae. The PCR assay was able to detect 0.01 ng of E. tarda, 0.1 ng of S. parauberis, and 1 ng of S. iniae genomic DNA. Furthermore, this technique was found to have high specificity when tested with related bacterial species. This method represents a cheaper, faster, and reliable alternative for identifying major bacterial pathogens in olive flounder, the most important farmed fish in Korea.     

Cell proliferation and neuroblast differentiation in the dentate gyrus of high-fat diet-fed mice are increased after rosiglitazone treatment

In this study, we determined how rosiglitazone (RSG) differentially affected hippocampal neurogenesis in mice fed a low-fat diet (LFD) or high-fat diet (HFD; 60% fat). LFD and HFD were given to the mice for 8 weeks. Four weeks after initiating the LFD and HFD feeding, vehicle or RSG was administered orally once a day to both groups of mice. We measured cell proliferation and neuroblast differentiation in the subgranular zone of the dentate gyrus using Ki67 and doublecortin (DCX), respectively, as markers. In addition, we monitored the effects of RSG on the levels of DCX and brain-derived neurotrophic factor (BDNF) in hippocampal homogenates. At 8 weeks after the LFD feeding, the numbers of Ki67- and DCX-positive cells as well as hippocampal levels of DCX and BDNF were significantly decreased in the RSG-treated group compared to the vehicle-treated animals. In contrast, the numbers of Ki67- and DCX-positive cells along with hippocampal levels of DCX and BDNF in the HFD fed mice were significantly increased in the RSG-treated mice compared to the vehicle-treated group. Our data demonstrate that RSG can modulate the levels of BDNF, which could play a pivotal role in cell proliferation and neuroblast differentiation in the hippocampal dentate gyrus.     

Comparison of acid-detergent lignin,alkaline-peroxide lignin,and acid-detergent insoluble ash as internal markers for predicting fecal output and digestibilily by caltie offered bermudagrass hays of varying nutrient composition

Background： The potential for acid-detergent insoluble ash （ADIA）, alkaline-peroxide lignin （APL）, and acid-detergent lignin （ADL） to predict fecal output （FO） and dry matter digestibility （DMD） by cattle offered bermudagrass [Cynodon doctylon （L） Pers.] hays of different qualities was evaluated. Eight ruminally cannulated cows （594 ± 35.5 kg） were allocated randomly to 4 hay diets： low （L）, medium low （ML）, medium high （MH）, and high （H） crude protein （CP） concentration （79, 111,131, and 164 g CP/kg on a DM basis, respectively）. Diets were offered in 3 periods with 2 diet replicates per period and were rotated across cows between periods. Cows were individually fed 20 g DM/kg of body weight in equal feedings at 08：00 and 16：00 h for a 10-d adaptation followed by a 5-d total fecal collection. Actual DM intake （DMI）, DMD, and FO were determined based on hay offered, ort, and feces excreted. These components were then analyzed for ADL, APL, and ADIA concentration to determine marker recovery and marker-based estimates of FO and DMD. Results： Forage DMI was affected by diet （P = 0.02）, and DMI from MH and H was greater （P 〈 0.05） than from L. Apparent DMD tended （P = 0.08） to differ among diets while FO （P = 0.20） was not affected by diet treatments. Average ADL recovery （1.16） was greater （P 〈 0.05） than that of ADIA （1.03） and APL （1.06）, but ADIA and APL did not differ （P = 0.42）. Estimates of FO and DMD derived using APL and ADIA were not different （P≥0.05） from total fecal collection while those using ADL differed （P 〈 0.05）. There was no diet by marker interaction （P≥ 0.22） for either FO or DMD. Conclusion： Acid-detergent insoluble ash and APL accurately predicted FO and DMD of cattle fed bermudagrass hay of varying nutrient composition. These internal markers may facilitate studies involving large numbers of animals and forages. Results from such studies may be used to develop improve     

Use of marine yeasts as an available diet for mass cultures of Moina macrocopa

A 4‐week feeding trial was conducted to test the use of marine yeasts purified from seawater and sediments as a dietary source in cultivating a cladoceran, Moina macrocopa, a potential alternative live food for fish larvae. Optimal growth conditions of two yeast strains were obtained for NaCl concentration, pH and temperature. Moina macrocopa was cultivated using different diets: marine yeasts (Debaryomyces hansenii Yeast‐14 and Candida austromarina Yeast‐16) and a commercial diet (Erythrobacter sp. Sπ‐I). The essential amino acids of both the yeast strains were nearly as great as those in M. microcopa. Further, the yeast‐fed M. macrocopa had essential amino acid profiles similar to the documented values for rotifers and Artemia enriched in microalgae and commercial diets. Erythrobacter sp. Sπ‐I lacked n‐3 polyunsaturated fatty acids, 20:5n‐3 and 22:6n‐3, which were also low but detected in both yeasts. An increase in the 20:5n‐3 [eicosapentaenoic acid (EPA)] and 22:6n‐3 [docosahexaenoic acid (DHA)] levels, compared with the levels in yeast strains themselves, was more pronounced in the 22:6n‐3 level of Moina fed the C. austromarina, resulting in a high DHA:EPA ratio. When the Moina diets were switched, their δ¹³C values shifted gradually towards the values of the switched diets. Diet switch from Erythrobacter sp. Sπ‐I to C. austromarina Yeast‐16 resulted in a more rapid turnover of Moina tissue carbon than that in the inverse case. When fed a mixed diet, the δ¹³C values of Moina tissue approached the value of marine yeasts immediately. These temporal changes in the δ¹³C values of Moina tissue indicate the preferential ingestion of marine yeasts and a selective assimilation of the carbon originated from marine yeasts. These findings suggest that marine yeasts, particularly C. austromarina Yeast‐16, are highly available to mass cultures of M. macrocopa, providing better nutritional and dietary values than the commercial diet (Erythrobacter sp. Sπ‐I).     

Design guidelines for the Dashilar,Beijing Open Green Space Redevelopment Project

When an urban redevelopment project is planned, the design needs to reflect the preferences of the users of the planned space. In China, however, the preferences of residents have rarely been reflected in projects dealing with public places such as open green spaces in urban settings. This paper employs three independent conjoint analyses covering components of open green space, including locational conditions, physical conditions, and greenery conditions in order to propose the most preferable design for a new open green space. The results of choice simulation showed that the users prefer the private garden style to the general public park style for the new open green space in Dashilar. Our research with three independent conjoint analyses is expected to provide specific guidelines for open green space design as a whole, which is intended to satisfy potential users of the space.