Performance evaluation in the growing of the stellate sturgeon fry in 35 days from hatching under the circumstances of enrichening food with probiotics

The main objective of the present paper was to evaluate the influence of the commercial probiotic BetaPlus® Ultra on the growth performance of the stellate sturgeon after 35 days of hatching, but the specific objective was to evaluate the food retention efficiency in the transition period from feeding with natural feed to that with commercial feed. For this purpose, a 93-day experiment was carried out with 6 experimental variants (5 different probiotic concentrations : V 1-1.28x1013 CFU, V2-2.56 x1013 CFU, V3 -3.84x1013 CFU, V4 – 5.12x1013 CFU, V5 -6.4x1013 CFU and V6- control variant, in duplicates). The experiment started with a number of 6000 exemplars of 35-day post hatched larvae (500 specimens/rearing unit) with a mean individual weight (± SD) of 0.35 ± 0.02 g and a total length between 3-5 cm. According to the rearing technology, sorting was carried out throughout the experimental period which led to the division of the experiment into 9 different experimental stages according to feeding protocol. Feeding efficiency, expressed by FCR and protein retention, indicated by PER shows an insignificant increase (p> 0.05) in the V2 variant and an insignificant decrease in the case where the probiotic (V6) was not administered. Therefore, according to this experiment, a concentration of 2.56x1013 CFU / kg of commercial probiotic BetaPlus® Ultra represents an optimum value for promoting the growth, feeding efficiency and retention of proteins of trout after more than one gram

An international inter-laboratory study on Nosema spp. spore detection and quantification through microscopic examination of crushed honey bee abdomens

Nosemosis is a microsporidian disease causing mortality and weakening of honey bee colonies, especially in the event of co-exposure to other sources of stress. As a result, the disease is regulated in some countries. Reliable and harmonised diagnosis is crucial to ensure the quality of surveillance and research results. For this reason, the first European Interlaboratory Comparison (ILC) was organised in 2017 in order to assess both the methods and the results obtained by National Reference Laboratories (NRLs) in counting Nosema spp. spores by microscopy. Implementing their own routine conditions of analysis, the 23 participants were asked to perform an assay on & nbsp;a & nbsp;panel of ten positive and negative samples of crushed honey bee abdomens. They were asked to report results from a qualitative and quantitative standpoint. The assessment covered specificity, sensitivity, trueness and precision. Quantitative results were analysed in compliance with international standards NF ISO 13528 (2015) and NF ISO 5725-2 (1994). Three results showed a lack of precision and five a lack of trueness. However, overall results indicated a global specificity of 98% and a global sensitivity of 100%, thus demonstrating the advanced performance of the microscopic methods applied to Nosema spores by the NRLs. Therefore, the study concluded that using microscopy to detect and quantify spores of Nosema spp. was reliable and valid.panel of ten positive and negative samples of crushed honey bee abdomens. They were asked to report results from a qualitative and quantitative standpoint. The assessment covered specificity, sensitivity, trueness and precision. Quantitative results were analysed in compliance with international standards NF ISO 13528 (2015) and NF ISO 5725-2 (1994). Three results showed a lack of precision and five a lack of trueness. However, overall results indicated a global specificity of 98% and a global sensitivity of 100%, thus demonstrating the advanced performance of the microscopic methods applied to Nosema spores by the NRLs. Therefore, the study conclude

Reliability of Morphological and PCR Methods for the Official Diagnosis of Aethina tumida (Coleoptera: Nitidulidae): A European Inter-Laboratory Comparison

International audienceThe Small Hive Beetle (Aethina tumida Murray, 1867) is an invasive scavenger of honeybees. Originally endemic in sub-Saharan Africa, it is regulated internationally in order to preserve the areas still free from this species. To ensure the reliability of official diagnoses in case of introduction, an inter-laboratory comparison was organised on the identification of A. tumida by morphology and real-time PCR. Twenty-two National Reference Laboratories in Europe participated in the study and analysed 12 samples with adult coleopterans and insect larvae. The performance of the laboratories was evaluated in terms of sensitivity and specificity. Sensitivity was satisfactory for all the participants and both types of methods, thus fully meeting the diagnostic challenge of confirming all truly positive cases as positive. Two participants encountered specificity problems. For one, the anomaly was minor whereas, for the other, the issues concerned a larger number of results, especially real-time PCR, which probably were related to inexperience with this technique. The comparison demonstrated the reliability of official diagnosis, including the entire analytical process of A. tumida identification: from the first step of the analysis to the expression of opinions. The performed diagnostic tools, in parallel with field surveillance, are essential to managing A. tumida introduction