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United States Department of Agriculture

Agricultural Research Service

Research Project: ASTRAGALUS AND OXYTROPIS POISONING IN LIVESTOCK

Location: Poisonous Plant Research

Title: Selenium

Authors
item Davis, Thomas
item Hall, Jeffery -

Submitted to: Reproductive Toxicology
Publication Type: Book / Chapter
Publication Acceptance Date: March 1, 2011
Publication Date: April 4, 2011
Citation: Davis, T.Z., Hall, J.O. 2011. Selenium. In: Gupta, R.C., editor. Reproductive and Developmental Toxicology. San Diego, CA. Academic Press. p. 61-8.

Interpretive Summary: Selenium is an essential nutrient that has a relatively narrow window between ingested amounts that result in deficiencies and those that cause toxicoses. Many species of animals have reduced conception rates when exposed to high concentrations of selenium. Historically, selenium toxicosis has been reported to cause abortion or Teratogenesis in many species. The reports in mammals have been difficult to prove and there are likely other factors that have in some cases led to misdiagnosis. However, Teratogenesis due to selenosis is well documented in avian species. Additionally, the testis is a specific target of selenium and it appears to be essential for maintaining a normal spermatogenesis and for male fertility. The importance of selenium in male reproduction has been known for decades as selenium imbalances have been known to cause reduced fertility, impaired sperm motility and abnormal tail morphology. Selenium deficiency and toxicity are problems which have caused extensive financial losses in the livestock industry and have been extensively researched. However, recent research demonstrates that there remains a significant amount of knowledge that needs to be discovered in order to fully understand all of the roles of selenium, especially with regards to reproductive effects. Since it is now known that different chemical forms of selenium can have different physiologic responses, it is now essential that we develop a better understanding of both the beneficial and detrimental effects of different chemical forms of selenium and to understand their relative roles in the toxic effects on reproduction. In this light, it is critical that researchers clearly identify chemical forms of selenium from field cases in order to adequately research the clinical syndromes with the correct chemical form of selenium under controlled conditions. There is also a need to understand the role of the many selenoenzymes in reproductive organs whose roles have not yet been determined.

Technical Abstract: Selenium deficiency and toxicity are problems which have caused extensive financial losses in the livestock industry and have been extensively researched. However, recent research demonstrates that there remains a significant amount of knowledge that needs to be discovered in order to fully understand all of the roles of selenium, especially with regards to reproductive effects. Since it is now known that different chemical forms of selenium can have different physiologic responses, it is now essential that we develop a better understanding of both the beneficial and detrimental effects of different chemical forms of selenium and to understand their relative roles in the toxic effects of reproduction. In this light, it is critical that researchers clearly identify chemical forms of selenium from field cases in order to adequately research the clinical syndromes with the correct chemical form of selenium under controlled conditions. There is also a need to understand the role of the many selenoenzymes in reproductive organs whose roles have not yet been determines.

Last Modified: 4/20/2014
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