Acetone and urea concentration in milk as indicators of the nutritional status and the composition of the diet of dairy cows

acetona acetone aliment pour animaux alimentation des animaux animal feeding animal health cetose cetosis chemical composition composition chimique cow milk dairy cows estado nutricional feeds ketosis lait de vache leche de vaca milk yield nutritional status nutritive value performance de reproduction piensos rendement laitier rendimiento lechero reproductive performance reproductividad sanidad animal urea uree vacas lecheras valeur nutritive valor nutritivo