BackgroundInnovations in fish nutrition act as drivers for the sustainable development of the rapidly expanding aquaculture sector. Probiotic dietary supplements are able to improve health and nutrition of livestock, but respective bacteria have mainly been isolated from terrestrial, warm-blooded hosts, limiting an efficient application in fish. Native probiotics adapted to the gastrointestinal tract of the respective fish species will establish within the original host more efficiently.ResultsHere, 248 autochthonous isolates were cultured from the digestive system of three temperate flatfish species. Upon 16S rRNA gene sequencing of 195 isolates, 89.7% (n = 175) Gram-negatives belonging to the Alpha- (1.0%), Beta- (4.1%) and Gammaproteobacteria (84.6%) were identified. Candidate probiotics were further characterized using in vitro assays addressing 1) inhibition of pathogens, 2) degradation of plant derived anti-nutrient (saponin) and 3) the content of essential fatty acids (FA) and their precursors. Twelve isolates revealed an inhibition towards the common fish pathogen Tenacibaculum maritimum, seven were able to metabolize saponin as sole carbon and energy source and two isolates 012 Psychrobacter sp. and 047 Paracoccus sp. revealed remarkably high contents of docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA). Furthermore, a rapid and cost-effective method to coat feed pellets revealed high viability of the supplemented probiotics over 54 d of storage at 4°C.ConclusionsHere, a strategy for the isolation and characterization of native probiotic candidates is presented that can easily be adapted to other farmed fish species. The simple coating procedure assures viability of probiotics and can thus be applied for the evaluation of probiotic candidates in the future.
Animal welfare is an essential component of dairy production and several systems exist to evaluate the welfare of dairy cows. Here, we review and compare three well-known systems that operate at farm level from around the world (FARM, Welfare Quality®, and The Code of Welfare) and discuss their advantages and limitations. Despite having some commonalities, the programs evaluate different elements. We also briefly review an emerging system (Integrated Diagnostic Welfare System) that might address some of the shortcomings of the existing systems, especially the possibility of automating the evaluation of animal well-being and identifying any cause of poor welfare. None of the aforementioned systems has been fully validated for their ability to assess animal welfare using independent measurements. The future holds increased attention around the well-being of dairy cows and increased use of sensing technologies. There is an urgent need for dairy welfare evaluation systems that are scientifically validated, holistic, and that can take advantage of the use of sensing technologies to continuously monitor animal welfare.
The hypothesis of the study was that feeding a relatively low amount of Se biofortified alfalfa hay during the dry period and early lactation would improve selenium status and glutathione peroxidase activity in dairy cows and their calves. Ten Jersey and 8 Holstein primiparous dairy cows were supplemented with Se biofortified (TRT; n = 9) or non-biofortified (CTR; n = 9) alfalfa hay at a rate of 1 kg/100 kg of BW mixed with the TMR from 40 d prior parturition to 2 weeks post-partum. Se concentration in whole blood, liver, milk, and colostrum, the transfer of Se to calves, and the glutathione peroxidase (GPx) activity were assessed. TRT had 2-fold larger (P < 0.05) Se in blood v. CTR that resulted in larger Se in liver and colostrum but not milk and larger GPx activity in plasma and erythrocytes but not in milk. Compared to CTR, calves from TRT had larger Se in blood but only a numerical (P = 0.09) larger GPx activity in plasma. A positive correlation was detected between Se in the blood and GPx activity in erythrocytes and plasma in cows. Our results demonstrated that feeding pregnant primiparous dairy cows with a relatively low amount of Se-biofortified alfalfa hay is an effective way to increase Se in the blood and liver, leading to greater antioxidant activity via GPx. The same treatment was effective in improving Se concentration in calves but had a modest effect on their GPx activity. Feeding Se biofortified hay increased Se concentration in colostrum but not in milk.
This study was performed to identify differences in the frequency of specific cytologic diagnoses obtained between specimens prepared by the filtration and ThinPrep (Cytyc, Marlborough, MA) techniques and to assess how these cytologic diagnoses correlated with pathologic findings. Data were collected from 2,347 voided urine specimens analyzed 8 months before and after ThinPrep implementation. Urine cytologic and bladder biopsy specimens were obtained as part of clinical follow-up, and positive diagnoses were considered evidence of malignancy. After ThinPrep implementation, the proportion of specimens diagnosed as negative significantly decreased (85.5% vs 78.6%; P<.001), clusters (5.8% vs 5.6%; P=.597) and positive (2.8% vs 3.3%; P=.143) diagnoses remained similar, and atypical (3.1% vs 8.4%; P<.001) and "suspicious" diagnoses (2.7% vs 4.1%; P<.001) increased. After 1 year of follow-up, there was no significant difference in the percentage of patients diagnosed with bladder carcinoma between the 2 methods for all cytologic categories.
This study investigated whether biotransformation and antioxidant enzymes of an organism tolerant to pollution such as the zebra mussel Dreissena polymorpha can be employed to evaluate the extent of urban water pollution. Activity changes of soluble and membrane bound glutathione S-transferase (s- and mGST), superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx) to environmental stress were explored in precultured mussels exposed for one day to one week at selected sites with reasonable anthropogenic impact. The enzymatic response of whole mussel tissue was compared to gill tissue. Changes in enzyme activity were accordant with the different pollution scenarios, as charges with polychlorinated biphenyls (PCB), dichlorodiphenyltrichloroethane (DDT) and other pesticides, as well as contamination with metals. Whereas in whole mussel tissue all analyzed enzymes responded with elevation, in gills inhibition took place with the exception of mGST. The results confirm the high sensitivity of gills, nevertheless enzymatic changes measured in whole mussel tissue provided the clearest results. Significant changes in GST, CAT and GPx enzyme activity were only observed at water temperatures above 20 degrees C. SOD activity was not restricted by temperatures and serves for this reason as a biomarker for oxidative stress at lower water temperatures. Discrepancies between biological and chemical evaluation of the sampling sites are presented and biomarker responses appraised.
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