Effect of Partial Replacement of Alfalfa Hay with Wheat Straw on Digestibility and Growth Performance of Fattening Male Lambs

The objective of this study was to evaluate the effect of partially replacing forage sources (alfalfa hay) with treated wheat straw on nutrient digestibility, chewing activity, blood metabolites, rumen fermentation, and performance of finishing lambs. Wheat straw (WS) was treated with 7 % sodium hydroxide, 3.5 % salt, and 3.3 % calcium carbonate and then ensiled for 2 months. Twenty-three male lambs (28 kg) were randomly allocated to three diets differing in forage sources: 1) control diet (100 % alfalfa hay), 2) 1/3 WS (67 % alfalfa hay and 33 % wheat straw) and 3) 2/3 WS (33 % alfalfa hay and 67 % wheat straw). Results indicated that ruminal degradability (24 and 48 h incubation) of treated wheat straw and alfalfa hay was similar, but higher than untreated straw (P