[Reduction of the polluting action of the swine excrements. The importance of feeding]

abattage d'animaux alimentation des animaux alimentazione zootecnica alimenti a base di soia alimentos derivados de la soja animal feeding antibiotici antibiotics antibiotique azote azoto cerdo creatinina creatinine digestibilidad digestibility faeces feces feci fourrage grain grain feed granos pienso heces lactation lattazione leucina leucine macellazione metabolism metabolisme metabolismo nitrogen nutritive value porcin proteine proteins raciones ration rations razioni sacrificio slaughtering soyfoods swine valeur nutritive valor nutritivo valore nutritivo