Estimation of microbial N flow from purine derivative urinary excretion in heep and goats fed diets with different alfalfa hay:concentrate ratios - Cantalapiedra-Hijar G; Molina-Alcaide E; Ramos S; Tejido ML; Yáñez-Ruiz DR; Carro MD (Ruminant Physiology: Digestion, Metabolism, And Effects Of Nutrition On Reproduction And Welfare, 2023)