Use of date palm leaves in high concentrate diets for lactating Friesian and Holstein cows

alimentation barley straw bovin cattle chemical composition composition chimique cows dairy cows dates datte diet dieta feeding feuille fruits frutas gain de poids ganado bovino ganancia de peso hojas lait leaves leche liveweight gain milk milk yield paille d'orge paja de cebada rendement laitier rendimiento lechero subproductos vaca vacas lecheras vache weight gain