Effect of selenite and selenised yeast supplementation on selenium concentration of Finnish organic milk – a farm study.

Experiment was conducted at 15 certified organic dairy farms in Eastern Finland during spring 2008. Farms were allocated to three balanced groups according annual milk yield, herd size and housing system. Three types of selenium (Se) supplementations: selenium yeast (SY), sodium selenite (SS) or their (50:50) combination (SYS) was used. Daily Se doses were adjusted according to milk yield basis (average 3 mg/d). Experimental model was 3 X 3 Latin square, consisting from 3 experiment periods. The length of each period was 28 days. RehuRaisio provided experimental feeds. In the end of each period bulk-tank milk samples were collected and analysed for Se at MTT Agrifood Research Finland. The Se supplementation form was crucial for milk Se concentration (P<0.001), when Se concentration of basic fodder was extreme low (<0.01 mg/kg DM). SS (n=15) resulted to milk Se concentration of 0.012 mg/kg, but SYS (n=15) resulted to 1.9-fold and SY (n=14) to 2.3-fold higher milk Se concentrations

Selenium concentration of Finnish organic milk - a farm survey

Bulk-tank milk samples were collected in January (2008) from 45 organic farms in Eastern Finland to examine their milk quality. Beside diets, current Se supplementation practices were also documented

Bioaccessibility of selenium after human ingestion in relation to its chemical species and compartmentalization in maize

International audienceSelenium is a micronutrient needed by all living organisms including humans, but often present in low concentration in food with possible deficiency. From another side, at higher concentrations in soils as observed in seleniferous regions of the world, and in function of its chemical species, Se can also induce (eco)toxicity. Root Se uptake was therefore studied in function of its initial form for maize (Zea mays L.), a plant widely cultivated for human and animal food over the world. Se phytotoxicity and compartmentalization were studied in different aerial plant tissues. For the first time, Se oral human bioaccessibility after ingestion was assessed for the main Se species (SeIV and SeVI) with the BARGE ex vivo test in maize seeds (consumed by humans), and in stems and leaves consumed by animals. Corn seedlings were cultivated in hydroponic conditions supplemented with 1 mg L−1 of selenium (SeIV, SeVI, Control) for 4 months. Biomass, Se concentration, and bioaccessibility were measured on harvested plants. A reduction in plant biomass was observed under Se treatments compared to control, suggesting its phytotoxicity. This plant biomass reduction was higher for selenite species than selenate, and seed was the main affected compartment compared to control. Selenium compartmentalization study showed that for selenate species, a preferential accumulation was observed in leaves, whereas selenite translocation was very limited toward maize aerial parts, except in the seeds where selenite concentrations are generally high. Selenium oral bioaccessibility after ingestion fluctuated from 49 to 89 % according to the considered plant tissue and Se species. Whatever the tissue, selenate appeared as the most human bioaccessible form. A potential Se toxicity was highlighted for people living in seleniferous regions, this risk being enhanced by the high Se bioaccessibility

Selenium content of Finnish oats in 1997-1999: effect of cultivars and cultivation techniques

Se-supplemented fertilization is the main factor affecting the selenium (Se) contents of cereals in Finland. Soil and climatic conditions determine the activity of selenate added to soils and bioavailability to plants. In the present study the Se contents and its variation in Finnish oats, the differences between oat cultivars and cultivation techniques were examined. The selenium (Se) contents of oats (Avena sativa L.) in Finland were examined during 1997-1999 in 3 types of trial: official variety, organic cultivation variety and organic vs. conventional cultivation trials. Farm samples were also examined. The mean Se contents of oats in official variety trials were 0.110, 0.120 and 0.160 mg kg-1 dry weight (dw) range 0.016-0.460 mg kg-1dw in 1997-1999, respectively. The mean Se contents in farm samples were 0.050 and 0.130 mg kg-1dw in 1998 and 1999, ranging between < 0.010 and 0.330 mg kg-1 dw. Considerable regional and seasonal variations existed. The Se contents of oats were significantly higher in 1999 probably due to the combined effect of not increased fertilizer level (from 6 to 10 mg Se kg-1 fertilizer) and very low precipitation in 1999. The Se contents of oats were significantly lower in organic cultivation, due to the absence of Se-supplemented fertilization. Significant (P < 0.001) cultivar differences were detected in official variety trials. The cultivars Veli and Leila showed higher levels of Se.;Tutkimus oli osa Kaura raaka-aineen laadunohjausjärjestelmä-hanketta, jossa selvitettiin laajasti suomalaisen kauran laatua ja soveltuvuutta elintarvikeja rehukäyttöön. Tavoitteena oli selvittää kauran seleenipitoisuuksia sekä lajikkeen ja luomuviljelyn vaikutusta seleenipitoisuuksiin. Näyteaineisto koostui MTT:n tutkimusasemien ja yhteistyökumppanien kaurakokeiden satonäytteistä sekä seleeniseurantatutkimuksen yhteydessä Kasvintuotannon tarkastuskeskuksesta saaduista tilanäytteistä. Virallisissa lajikekokeissa kauran keskimääräiset seleenipitoisuudet olivat 0,110, 0,120 and 0,160 mg kg-1 kuiva-ainetta vuosina 1997-1999 vaihteluvälin ollessa 0,016-0,460 mg kg-1 kuiva-ainetta. Tilanäytteiden keskimääräiset seleenipitoisuudet olivat 0,050 and 0,130 mg kg-1 kuiva-ainetta vuosina 1998-1999, vaihteluväl

Selenium content of Finnish oats in 1997-1999: effect of cultivars and cultivation techniques

Se-supplemented fertilization is the main factor affecting the selenium (Se) contents of cereals in Finland. Soil and climatic conditions determine the activity of selenate added to soils and bioavailability to plants. In the present study the Se contents and its variation in Finnish oats, the differences between oat cultivars and cultivation techniques were examined. The selenium (Se) contents of oats (Avena sativa L.) in Finland were examined during 1997-1999 in 3 types of trial: official variety, organic cultivation variety and organic vs. conventional cultivation trials. Farm samples were also examined. The mean Se contents of oats in official variety trials were 0.110, 0.120 and 0.160 mg kg-1 dry weight (dw) range 0.016-0.460 mg kg-1dw in 1997-1999, respectively. The mean Se contents in farm samples were 0.050 and 0.130 mg kg-1dw in 1998 and 1999, ranging between < 0.010 and 0.330 mg kg-1 dw. Considerable regional and seasonal variations existed. The Se contents of oats were significantly higher in 1999 probably due to the combined effect of not increased fertilizer level (from 6 to 10 mg Se kg-1 fertilizer) and very low precipitation in 1999. The Se contents of oats were significantly lower in organic cultivation, due to the absence of Se-supplemented fertilization. Significant (P < 0.001) cultivar differences were detected in official variety trials. The cultivars Veli and Leila showed higher levels of Se.

Symposium on 'Geographical and geological influences on nutrition' : factors controlling the distribution of selenium in the environment and their impact on health and nutrition

Se is essential to human and animal health but can be toxic in excess. An interest in its geochemistry has developed alongside a greater understanding of its function in a number of health conditions. Geology exerts a strong control on the Se status of the surface environment; low-Se rock-types (0.05–0.09 mg Se/kg) make up the majority of rocks occurring at the Earth’s surface, which in turn account for the generally low levels of Se in most soils. However, there are exceptions such as associations with sulfide mineralisation and in some types of sedimentary rocks (e.g. black shales) in which contents of Se can be much higher. Baseline geochemical data now enable a comparison to be made between environmental and human Se status, although a direct link is only likely to be seen if the population is dependent on the local environment for sustenance. This situation is demonstrated with an example from the work of the British Geological Survey in the Se-deficiency belt of China. The recent fall in the daily dietary Se intake in the UK is discussed in the context of human Se status and declining use of North American wheat in bread making. Generally, US wheat has ten times more Se than UK wheat, attributed to the fact that soils from the wheat-growing belt of America are more enriched in Se to a similar order of magnitude. In agriculture effective biofortification of crops with Se-rich fertilisers must be demonstrably safe to the environment and monitored appropriately and baseline geochemical data will enable this process to be done with confidence