Advances in selenium supplementation: From selenium-enriched yeast to potential selenium-enriched insects, and selenium nanoparticles.

Selenium (Se) is an essential micronutrient that plays an important role in animal and human development and physiological homoeostasis. This review surveys the role of Se in the environment, plants and animal bodies, and discusses data on Se biofortification with different sources of supplementation, from inorganic to organic forms, with special focus on Se-enriched yeast (Se-yeast). Although Se-yeast remains one of the main sources of organic Se, other emerging and innovative sources are reviewed, such as Se-enriched insects and Se-nanoparticles and their potential use in animal nutrition. Se-enriched insects are discussed as an option for supplying Se in organic form to livestock diets. Se-nanoparticles are also discussed, as they represent a more biocompatible and less toxic source of inorganic Se for animal organisms, compared to selenite and selenate. We also provide up to date information on the legal framework in the EU, USA, and Canada of Se that is contained in feed additives. From the scientific evidence available in the literature, it can be concluded that among the inorganic forms, sodium selenite is still one of the main options, whereas Se-yeast remains the primary organic form. However, other potential sources such as Se-enriched insects and Se-nanoparticles are being investigated as they could potentially combine a high bioavailability and reduced Se emissions in the environment.

Validation of a multi-analyte HPLC method for the determination of carotenoids used as feed additives in fish and poultry feed: results of an interlaboratory study.

The performance characteristics of a multi-analyte method for the determination of all 10 carotenoids authorised as feed additives within the EU were assessed via an interlaboratory study. The analytical method is based on reversed phase high performance liquid chromatography (RP-HPLC) coupled to an optical detector set at 410 nm. The analysis is particularly challenging due to the presence of various stereoisomers of each carotenoid, and the use of these compounds via natural or synthetic formulations, requiring a special sample preparation. EU regulations specifying the conditions of use set legal limits for these substances in compound feedingstuffs ranging from 6 mg kg-1 to 138 mg kg-1, depending on the individual carotenoid and the target animal for which the feed is supplemented with this carotenoid. The purpose of the multi-analyte method validated in this paper is to facilitate the monitoring of carotenoids at relevant levels when used as feed additives in compound feedingstuffs and pre-mixtures. The interlaboratory study delivered precision data for 43 different analyte/mass fraction/matrix combinations, covering a mass fraction range of the target analytes from 2.6 mg kg-1 to 3861 mg kg-1. The relative standard deviations for repeatability (RSDr) varied from 2.2 to 16.2 % with a mean value of 6 %, while the relative standard deviations for reproducibility (RSDR) varied from 6.8 to 39 % with a mean value of 21 %. Given the broad scope of the method covering 10 carotenoids added to compound feedingstuffs and pre-mixtures via different formulations, this multi-analyte method is considered fit for the intended purpose.

Application of the CEN/ISO Standard for Phytase Activity Measurements to a New Phytase Product: Determination of a Robust Conversion Factor by an Interlaboratory Study for Screening Feed Samples.

Background: Phytase-based preparations are important feed additives currently authorised in the European Union (EU). The European Standard (EN) and International Organization for Standardization (ISO) standard 30024 describes a harmonized method for the determination of phytase activity and is fit-for-purpose for official control of a group of phytase products. However, it is not suitable for the determination of the phytase activity of a new feed additive encoded as 4a16 in the EU Register of Feed Additives, to which a slightly different phytase activity definition has been attributed. Objective: To establish a robust conversion factor to support official control laboratories that apply the EN ISO method when monitoring feed products containing 4a16. Methods: The phytase activity of test materials was determined by the participants using the EN ISO and/or the "applicant" methods. Results: Robust relative SDs for repeatability and for reproducibility of the methods applied for the determination of the phytase activity in the materials containing the 4a16 feed additive ranged from 2.6 to 22% (EN ISO method) and from 2.4 to 39% (applicant method). Conclusions: The data obtained confirmed the performance characteristics published for other phytase-based feeds in the related standard methods. These results allowed us to estimate a factor of 2.68 to convert phytase activities measured with the EN ISO method into the enzyme activity measured with the applicant method. Highlights: The obtained conversion factor will allow EU official laboratories to screen feed samples supplemented with the 4a16 phytase by applying EN ISO Standard 30024.

Detection of banned meat and bone meal in feedstuffs by near-infrared microscopic analysis of the dense sediment fraction.

In this paper we present an alternative method for detection of meat and bone meal (MBM) in feedstuffs by near-infrared microscopic (NIRM) analysis of the particles in the sediment fraction (dense fraction (d >1.62) from dichloroethylene) of compound feeds. To apply this method the particles of the sediment fraction are spread on a sample holder and presented to the NIR microscope. By using the pointer of the microscope the infrared beam is focussed on each particle and the NIR spectrum (1112-2500 nm) is collected. This method can be used to detect the presence of MBM at concentrations as low as 0.05% mass fraction. When results from the NIRM method were compared with the classical microscopic method, a coefficient of determination (R2) of 0.87 was obtained. The results of this study demonstrated that this method could be proposed as a complementary tool for the detection of banned MBM in feedstuffs by reinforcement of the monitoring of feeds.