Ruminal, post-ruminal and total tract crude protein disappearance of alfalfa hay and barley grain were measured using in vivo, in situ mobile bag and three-step in situ/in vitro enzyme procedures (3-step). For in vivo, four Baluchi lambs (49.4 ± 3.5 kg, body weight) were used in a 2 × 2 Latin square design within 2 periods (24 days of each period). Experimental diets were made of two alfalfa ha...