Copper and selenium supplementation of ewes grazing on pastures low in copper and selenium: Effect on reproduction and concentration of plasma copper and blood selenium during pregnancy

Abstract

Influence of copper and selenium supplementationi n SA Mutton Merino ewes, kept on pastures with low copper and selenium concentrations, was investigated. Ewes which came into oestrus and conceived during March to April, were found to have concentrations of plasma copper of 60 to 80 pg /dl. Inadequare copper intake by ewes during late pregnancyr esultedi n decreasedc oncentrations of plasma copper, thereby leading to lorv concentrations of copper in the liver of young lambs. Selenium supplementation of ewes grazing pastures with a selenium content of 0,03-0,09 pg Se/g DM, has been found to raise concentrations of blood selenium but had no effect on the concentrations of selenium in the liver and kidneys of young lambs.

Die invloed van koper- en seleniumaanvullingb y SA Vleismerinoooie, wat op weiding met 'n lae koper- en seleniumkonsentrasie aangehou is, is ondersoek. Ooie wat tydens Maart tot April in es[us gekom en suksesvol gepaar is, het    plasmakoperkonsentrasies van 60 nt B0 *g ldl gehad. Onvoldoende koperinname tydens laatdragtigheid het tot 'n daling in die plasmakoperkonsentrasivea n die ooi gelei, terwyl die lewerkoperkonsentrasivea n hierdie lammers kort na geboortea bnormaall aag was. Seleniumaanvullingv an ooie op weiding mel 'n seleniumkonsenrasivea n 0,03-0,09 pg Se/g DM, het   bloedseleniumkonsentrasiesvaono ie verhoog, maar het min invloed op die lewer- en nierseleniumkonsentrasievsa n lammers kort na geboorte gehad.

Keywords: Blood selenium, copper supplementiation, fertility, plasma copper, pregnancy, selenium supplementation,