Complementary feeding stuff rich in trace elements,...
Selenium (Se) is an essential component of an enzyme (glutathione peroxydase) which aids in an important antioxidant that detoxifies lipo- and hydrogen peroxides that are toxic to cell membranes and can build up during exercise and in some disease states.
Selenium (Se) is an essential component of an enzyme (glutathione peroxydase) which aids in an important antioxidant that detoxifies lipo- and hydrogen peroxides that are toxic to cell membranes and can build up during exercise and in some disease states. It supports vitamin E and muscle function. Se plays also a role in the control of thyroid hormone metabolism.
Common feed stuffs: 0.01 to 0.3 mg/kg dry matter.
Daily requirements (NRC, 2007):
0.1 mg/kg dry matter. Maximum: 2 mg/kg dry matter.
N.B. 500 kg horse eats approximately 2% of its body weight per day i.e. 10kg dietary DM/day.
Myopathy (muscle disease): pale muscles, weakness, impaired locomotion, difficulty in suckling and swallowing, respiratory distress, impaired cardiac function. The clinical and morphologic manifestations of Se deficiency are affected by the concomitant vitamin E status.
Blindness, head pressing, perspiration, abdominal pain, colic, diarrhoea, increased heart and respiration rates, lethargy, death. Hair loss and changes in hooves after an acutely high dose of selenium. Chronic Se toxicity is characterized by alopecia (mane and tail) as well as cracking of the hooves around the coronary band.
When problems may occur?
- Alkaline soils are more conducive to plants accumulating Se. Drought conditions encourage deeper root growth where Se concentrations in the soil may be greater and also encourage animals to eat accumulator plants that might otherwise be ignored and can result in toxicities when consumed (woody aster-Xylorhiza, goldenweed-Oonopsis, milk vetch-Astragalus).
- Alkali treatment of roughage.
- Areas of Se deficiency in soils include New Zealand, parts of Scotland, eastern and western states of the USA, Northern Germany.