ALKALINE TREATMENT OF BARLEY STRAW AND ITS EFFECT ON DIGESTIBILITY, RUMEN FERMENTATION, FEEDLOT CATTLE PERFORMANCE AND PROFITABILITY

Micro-machine technology may provide cost-savings to feedlot producers, but they are unable to deliver limestone and salt into feedlot rations. Two experiments were conducted to evaluate the effectiveness of treating barley straw with calcium oxide to improve forage quality and provide a calcium source in wheat-based finishing diets. Additionally, the impact of removing calcium (limestone) and salt from supplements was examined. Barley straw was treated with 5% CaO and hydrated to 50% moisture, then stored for 60 h before feeding or sampling in the trials. The first experiment examined in vitro and in situ trial improvements in forage digestibility associated with CaO treatment of barley straw and compared it to barley and corn silage. CaO did not improve (P=0.99) the in vitro NDFD of barley straw but did increase (P0.05). Rumen parameters (VFA, NH3, protozoa, rumen microbial N, pH) were not affected by treatment, with the exception of maximum rumen pH being reduced (P0.05). In the second trial, ADG and feed efficiency did not differ between steers fed barley silage and CaOS-no NaCl diets or straw+CaO diets, and was higher than barley straw and CaOS (with salt) diets (P<0.01). Carcass and liver abscess scores did not differ among diets, with the exception of a tendency for increased dressing percentage when barley silage was included in the diet (P