Economic values of supply chain productivity and quality traits calculated for a farmed European whitefish breeding program

Economic values of different fish traits are needed to direct breeding programs to optimize economic benefits for aquaculture industry. The aim of this article is to highlight and calculate how different traits affect the value of farmed fish supply chain. Supply chain approach is needed to calculate economic impact of fish traits because several fish traits affect costs and returns not only in fish farming but also at the processing and retail level. In this article, economic values are calculated for 14 productivity and product quality traits in European whitefish (Coregonus lavaretus). Productivity affecting traits, such as growth, mortality and different yields, are included in the study. In addition, economic values are calculated for several quality traits like fillet gaping, appearance and fat content of flesh.

Productivity traits had the highest economic importance if the traits could be improved. However, quality traits may cause even higher economic losses, if the quality decreases. Thus, the management of the breeding program should pay simultaneous attention to both quality and productivity traits.     

Variation in nocturnality and circadian activity rhythms between photoresponsive F344 and nonphotoresponsive Sprague Dawley rats

Background

Variation in circadian rhythms and nocturnality may, hypothetically, be related to or independent of genetic variation in photoperiodic mediation of seasonal changes in physiology and behavior. We hypothesized that strain variation in photoperiodism between photoperiodic F344 rats and nonphotoperiodic Harlan Sprague Dawley (HSD) rats might be caused by underlying variation in clock function. We predicted that HSD rats would have more activity during the day or subjective day, longer free-running rhythms, poor entrainment to short day length, and shorter duration of activity, traits that have been associated with nonphotoperiodism in other laboratory rodent species, relative to F344 rats. An alternative hypothesis, that differences are due to variation in melatonin secretion or responses to melatonin, predicts either no such differences or inconsistent combinations of differences.

Methods

We tested these predictions by examining activity rhythms of young male F344 and HSD rats given access to running wheels in constant dark (DD), short day length (L8:D16; SD), and long day length (L16:D8; LD). We compared nocturnality (the proportion of activity during night or subjective night), duration of activity (alpha), activity onset and offset, phase angle of entrainment, and free running rhythms (tau) of F344 and HSD rats.

Results

HSD rats had significantly greater activity during the day, were sometimes arrhythmic in DD, and had significantly longer tau than F344 rats, consistent with predictions. However, HSD rats had significantly longer alpha than F344 rats and both strains entrained to SD, inconsistent with predictions.

Conclusion

The ability of HSD rats to entrain to SD, combined with longer alpha than F344 rats, suggests that the circadian system of HSD rats responds correctly to SD. These data offer best support for the alternative hypothesis, that differences in photoresponsiveness between F344 and HSD rats are caused by non-circadian differences in melatonin secretion or the response to melatonin.     

Macromolecular depletion modulates the binding of red blood cells to activated endothelial cells

Adhesion of red blood cells (RBCs) to endothelial cells (ECs) is usually insignificant but an enhanced adhesion has been observed in various diseases associated with vascular complications. This abnormal adhesion under pathological conditions such as sickle cell disease has been correlated with increased levels of various plasma proteins but the detailed underlying mechanism(s) remains unclear. Usually it is assumed that the proadhesive effects of plasma proteins originate from ligand interactions cross-linking receptors on adjacent cells, but explicit results detailing binding sites or receptors for some proteins (e.g., fibrinogen) on either RBC or EC surfaces that would support this model are missing. In this study, the authors tested whether there is an alternative mechanism. Their results demonstrate that dextran 2 MDa promotes the adhesion of normal RBCs to thrombin-activated ECs and that this effect becomes more pronounced with increasing thrombin concentration or with prolonged thrombin incubation time. It is concluded that depletion interaction originating from nonadsorbing macromolecules (i.e., dextran) can modulate the adhesion of red blood cells to thrombin-activated EC. This study thereby suggests macromolecular depletion as an alternative mechanism for the adhesion-promoting effects of nonadsorbing plasma proteins. These findings should not only aid in getting a better understanding of diseases associated with vascular complications but should also have many potential applications in biomedical or biotechnological areas that require the control of cell-cell or cell surface interactions.     

Identification and differentiation of Taylorella equigenitalis and Taylorella asinigenitalis by lipopolysaccharide O-antigen serology using monoclonal antibodies

Lipopolysaccharides (LPSs) from Taylorella equigenitalis, the causative agent of contagious equine metritis, and T. asinigenitalis were compared by sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE). Lipopolysaccharide profiles of 11 T. equigenitalis strains were similar, but different from the profiles of 3 T. asinigenitalis strains, and the profiles of 2 T. asinigenitalis strains were similar to each other. The serological specificities of the LPSs from these 14 strains were examined by immunoblotting and enzyme-linked immunosorbent assay with monoclonal antibodies (MAbs) to the LPSs of the T. equigenitalis and T. asinigenitalis type strains and T. asinigenitalis strain 2329–98. A MAb to T. equigenitalis LPS O-polysaccharide (O-PS) (M2560) reacted with LPSs from all T. equigenitalis strains but did not react with LPSs from the 3 T. asinigenitalis strains or with 43 non-Taylorella bacteria. Three MAbs to the T. asinigenitalis type strain LPS O-PS or core epitopes (M2974, M2982, M3000) reacted with the homologous strain and T. asinigenitalis strain Bd 3751/05, but not with any of the other bacteria. Five MAbs to T. asinigenitalis 2329–98 LPS O-PS or core epitopes (M2904, M2907, M2910, M2923, M2929) reacted only with this strain. Proton nuclear magnetic resonance spectra of the O-PSs of the type strains of T. equigenitalis and T. asinigenitalis provided fingerprint identification and differentiation of these 2 organisms. The serological results were consistent with our previous finding that the O-antigen of the type strain of T. equigenitalis, being a linear polymer of disaccharide repeating [→4)-α-L-GulpNAc3NAcA-(1→4)-β-D-ManpNAc3NAcA-(1→] units, differs from that of the T. asinigenitalis O-antigen polymer that is composed of repeating [→3)-β-D-QuipNAc4NAc-(1→3)-β-D-GlcpNAmA-(1→] units. Lipopolysaccharide O-PS could be a specific marker for identification and differentiation of T. equigenitalis and T. asinigenitalis, and provide the basis for the development of specific detection assays for T. equigenitalis.     

A retrospective diagnostic laboratory survey of antimicrobial resistance in fecal Escherichia coli isolated from spring calves in western Canada

Diagnostic laboratory data on antimicrobial susceptibility of Escherichia coli isolated from feces of spring calves were evaluated retrospectively for the 5-year period from 1999 to 2003. The antimicrobials to which resistance was most prevalent were tetracycline, ampicillin, and trimethoprim/sulphamethoxazole. Resistance to 3 or more antimicrobials was found in 52.5% [95% confidence interval (CI): 47.9 to 56.6] of the E. coli isolates. Incomplete records reduced the usefulness of the diagnostic laboratory data for surveillance. Standardized patient information submitted by veterinary clinics would increase the value of this data for surveillance.     

Reproductive Performance of Pigmented and Albino Female Channel Catfish Induced to Spawn with HCG or Ovaprim

Reproductive performance of albino and pigmented channel catfish ( Ictalurus punctarus ) females was compared when spawning was induced with HCG (human chorionic gonadotropin) or Ovaprim ³ (domperidone and [d-Ala⁶, Pro⁹ NEt]-luteinizing hormone-releasing hormone). In 1985, only HCG was used to induce spawning. Albino females required more injections, had a longer latency period from time of first injection to spawning, and had lower spawning success (30%) than pigmented females (77%). No differences were observed between albino and pigmented females for time-of-day of spawning, number of eggs obtained by manual stripping, and number of eggs/kg body weight. In 1988, HCG, Ovaprim, and saline (control) were used to induce spawning. HCG induced spawning in 80% of albino and 71% of pigmented females. Ovaprim induced 67% of pigmented females to spawn, but only 2 of 5 albino females spawned. One of four pigmented females injected with saline spawned. Albino females yielded 40–50% fewer eggs/kg body weight than pigmented females. Other performance characteristics for albino and pigmented females were similar whether injected with HCG or Ovaprim. High temperatures encountered during the 1985 spawning season my have had a differential effect on albino and pigmented fish and may account for some differences in spawning success.     

Unexpected Neurotoxicity in Dogs Receiving a Cyclophosphamide, Dactinomycin, and 5-Fluorouracil Chemotherapy Protocol

An inexpensive combination chemotherapy protocol containing cyclophosphamide, dactinomycin, and 5-fluorouracil was evaluated in dogs with carcinomas. Fifteen dogs were entered in this study, and there were 1 complete response and 2 partial responses among 12 evaluable dogs. However, 6 of 15 dogs (40%) developed neurotoxicity. The neurotoxicity of this protocol was compared with a previous 5-fluorouracil-containing protocol and found to be significantly higher. Due to the unacceptably high rate of neurotoxicity, this protocol cannot be recommended for use in dogs with cancer.     

Control of blue mold (Penicillium expansum) by fludioxonil in apples (cv Empire) under controlled atmosphere and cold storage conditions

A reduced risk fungicide, fludioxonil, was tested for its efficacy against blue mold caused by thiabendazole-resistant and -sensitive Penicillium expansum (Link) Thom in apples under three storage conditions. In a co-treatment, fludioxonil and inoculum were applied together to test the protective activity of the fungicide on wounds that had been aged for 1 or 2 days. The fungicide was also tested for its curative activity in post-inoculation treatment on apples that had been inoculated for 1 or 2 days. Fludioxonil was very effective as co-treatment and as post-inoculation treatment. At a concentration of 300 mg litre(-1), fludioxonil gave complete control of post-harvest blue mold caused by the thiabendazole-resistant and -sensitive P expansum for 105 days in controlled atmosphere (CA) storage at 2 (+/-1) degrees C, for 42 days in common cold storage at 4 (+/-1) degrees C and also in a shelf-life study for 6 days at 20 (+/-1) degrees C. Comparison on the effect of fludioxonil in CA storage and common cold storage showed that higher concentrations of fungicide were needed in cold storage than in CA storage. Fludioxonil at a concentration of 450 mg litre(-1), gave 98 and 92% control of blue mold of apples in the simulated shelf-life studies after CA and common cold storages, respectively. Fludioxonil has a potential to be incorporated in the fungicide resistance management strategies for control of blue mold in apples stored for 105 days.