Rare earths as a feed additive for poultry

additif aux aliments des animaux aditivos de piensos alimentation des animaux animal feeding aves de corral canal animal canard carcasse carcasses carne china chine diet dieta ducks egg production eggs elementos de tierras raras feed additives feed conversion efficiency gain de poids ganancia de peso huevos liveweight gain meat meat yield oeuf oligoelementos paloma pato pigeon pigeons poultry production d'oeufs rare earth elements rendement en viande trace elements viande volaille weight gain