L.W.D. van Raamsdonk

Hypoglycin A Concentrations in Maple Tree Species in the Netherlands and the Occurrence of Atypical Myopathy in Horses.

Background Atypical myopathy (AM) in horses is caused by the plant toxin hypoglycin A, which in Europe typically is found in the sycamore maple tree (Acer pseudoplatanus). Owners are concerned about whether their horses are in danger if they graze near maple trees. Hypothesis/Objectives To measure hypoglycin A in the most common maple tree species in the Netherlands, and to determine whether concentration of toxin is a predictor of AM in horses. Methods A total of 278 samples of maple tree leaves, sprouts, and seeds were classified by species. Mean concentrations of hypoglycin A were compared for the type of sample, the season and the occurrence of AM in the pasture (non‐AM versus AM). Statistical analysis was performed using generalized a linear model (SPPS22). Results Almost all Acer pseudoplatanus samples contained hypoglycin A, with concentrations differing significantly among sources (P < .001). Concentrations were significantly higher in seeds from the AM group than in seeds from the non‐AM group (856 ± 677 and 456 ± 358 mg/kg, respectively; P = .039). In sprouts and leaves this was not the case. Acer platanoides and Acer campestre samples did not contain detectable concentrations of hypoglycin A. Conclusions and clinical importance Acer platanoides and campestre seem to be safe around paddocks and pastures, whereas almost all Acer pseudoplatanus samples contained hypoglycin A. In all AM cases, Acer pseudoplatanus was found. Despite significantly higher concentration of hypoglycin A in seeds of pastures where AM has occurred, individual prediction of AM cannot be made by measuring these concentrations because of the high standard deviation.

Exposure assessment of cattle via roughages to plants producing compounds of concern.

Food producing animals are exposed to biologically active plant compounds through feed and roughages, presenting a potential risk to the animal but also consumers of food of animal origin. To evaluate to which plant compounds of concern dairy cows in the Netherlands are exposed, a ranking filter model was developed, combining information on abundance of plant species in vegetation plots in the Netherlands (183,905 plots of three different vegetation types) with plant-compound combinations (700), and with consumption data of fresh grass, grass silage and corn silage by cattle. The most abundant plant genera are those producing cyanogenic glycosides, coumarins and benzofuranocoumarins, being predominantly fodder plants (alfalfa, clover and some grasses) considered to be safe. Highest exposures were estimated for plant genera producing piperidine alkaloids (horsetail), furanocoumarins (parsley and relatives), pyrrolizidine alkaloids (Symphytum, Senecio, Leucanthemum, Eupatorium) and essential oils. The current results allow to prioritise future scientific research on these compounds.

New feed ingredients : the insect opportunity

ABSTRACT In the framework of sustainability and a circular economy, new ingredients for feed are desired and, to this end, initiatives for implementing such novel ingredients have been started. The initiatives include a range of different sources, of which insects are of particular interest. Within the European Union, generally, a new feed ingredient should comply with legal constraints in terms of ‘yes, provided that’ its safety commits to a range of legal limits for heavy metals, mycotoxins, pesticides, contaminants, pathogens etc. In the case of animal proteins, however, a second legal framework applies which is based on the principle ‘no, unless’. This legislation for eradicating transmissible spongiform encephalopathy consists of prohibitions with a set of derogations applying to specific situations. Insects are currently considered animal proteins. The use of insect proteins is a good case to illustrate this difference between a positive, although restricted, modus and a negative modus for allowing animal proteins. This overview presents aspects in the areas of legislation, feed safety, environmental issues, efficiency and detection of the identity of insects. Use of insects as an extra step in the feed production chain costs extra energy and this results in a higher footprint. A measure for energy conversion should be used to facilitate the comparison between production systems based on cold- versus warm-blooded animals. Added value can be found by applying new commodities for rearing, including but not limited to category 2 animal by-products, catering and household waste including meat, and manure. Furthermore, monitoring of a correct use of insects is one possible approach for label control, traceability and prevention of fraud. The link between legislation and enforcement is strong. A principle called WISE (Witful, Indicative, Societal demands, Enforceable) is launched for governing the relationship between the above-mentioned aspects. GRAPHICAL ABSTRACTIn the framework of sustainability and a circular economy, new ingredients for feed are desired and, to this end, initiatives for implementing such novel ingredients have been started. The initiati...

Microscopic recognition and identification of fish meal in compound feeds

ABSTRACT Fish meal is an accepted ingredient in compound feed. Unauthorised application is primarily enforced by visual inspection, i.e., microscopy. In order to document the visually available diversity, fragments of bones and scales of 17 teleost fish species belonging to seven different orders were investigated for their diversity in the presence of structural elements: lacunae and canaliculae in bone fragments and type of growth rings and teeth of scale fragments. Despite the classical division into cellular bones and acellular bones of teleost fish, i.e., whether or not possessing osteocytes, the current examinations revealed patterns of lacunae, in some types accompanied with canaliculae, in all 17 species investigated. In total seven types of bone structures were defined, and six types of scale structures. Profiles with the relative frequency of each bone type per species were established. The share of acellular bone fragments appeared to be related to the evolutionary position of the species. Results of proficiency tests for the detection of fish meal reveal that in most cases the sensitivity and specificity for the detection of fish meal ranges from sufficient to perfect. Only some specified circumstances can hamper proper recognition and identification, most notably salmon bone fragments mimicking bone fragments from terrestrial animals, and pieces of hydrolysed proteins or minerals mimicking acellular fish bone fragments. The expertise gained in this study would help to improve the distinction between fish meal and terrestrial animal material in compound feed, and it supports the application of the species-to-species ban with respect to the valorisation of by-products from fish farms in aquafeed. In a broader perspective, the current expertise might be helpful to detect fraud throughout the feed/food production chain. The matrix of characteristics versus species is implemented in a data model running in the expert system ‘Determinator’ for facilitating identification.