The excretion by sheep of⁷⁵selenium incorporated into red clover (Trifolium pratenseL.): The chemical nature of the excreted selenium and its uptake by three plant species

Haematological, Blood and Rumen Chemistry Changes in Lambs Following Supplementation with Se-yeast

“…Low absorption of selenium in ruminants is believed to result from reduction of dietary selenium to insoluble forms such as elemental selenium or selenides in the rumen environment (Peterson and Spedding 1963;Várady et al 2005).…”

Utilization of protozoal selenium in young goats

“…Researchers surmised that this could be the reason for the low net absorption of Se among ruminants. The reduction-reactions happening in the rumen could also contribute to the low turnover of Se (Cousins and Cairney, 1961;Peterson and Spedding, 1963;Harrison and Conrad, 1984). Although there was an increasing evidence of Se trapping by microbial rumen population, our earlier study showed that bacterial-Se collected from the rumen of wethers was not fully available for absorption in the intestine of mice (Serra et al, 1997).…”

Utilization of microbial selenium collected from the rumen of sheep

“…Serra et al (1994) demonstrated that the bioavailability of selenite and selenate is similar in providing supplemental Se to sheep. Conversely, Se absorption among ruminants is low after its incorporation into microbial tissue under a highly reduced rumen environment (Cousins and Cairney, 1961;Peterson and Spedding, 1963;Hidiroglou et al, 1968;Paulson et al, 1968;Harrison and Conrad, 1984;Hudman and Glenn, 1984;Lyons et al, 2006). In vitro experiments revealed that about 40% of rumen microbial selenite is converted to an insoluble form, while the incorporation of Se into microbial cell walls is more efficient and faster.…”