Concentrations of some mineral elements in the fur of silver foxes in the period of fur maturity after administration of zinc, silicon and selenium salt to feed rations

application rates berilio beryllium calcio calcium cinc cobre copper cuivre dose d'application estroncio feed supplements fer fourrure foxes furs hierro iron lead manganese manganeso nutritive value plomb plomo potasio potassium raciones ration rations renard rubidio rubidium sales salts sel selenio selenium silicio silicium silicon strontium sulfate de zinc sulfato de cinc suplementos de piensos valeur nutritive valor nutritivo zinc zinc sulphate zorro