[Rearing of young breeding sows: Bad fertility calls rentability in question]

age alimentation des animaux animal feeding boars cerdas ciclo estral crecimiento croissance cycle oestral edad fertilidad fertilite fertility gain de poids ganancia de peso gestion growth management oestrous cycle performance de reproduction peso poids rearing techniques reproductive performance reproductividad sows stimuli stimulus tejido adiposo tissu adipeux truie verraco verrat weight weight gain