title: Effect of age and dietary protein level on ovine nitrogen metabolism--I. Evidence of comparable metabolizable nitrogen availability.
mesh_terms: D000375:Aging; D000596:Amino Acids / Q000097:blood; D000818:Animals; D001835:Body Weight; D004044:Dietary Proteins / Q000378:metabolism*; D005260:Female; D009584:Nitrogen / Q000378:metabolism* / Q000652:urine; D012756:Sheep
chemical_list: D000596:Amino Acids; D004044:Dietary Proteins; D009584:Nitrogen