Background and Objectives: Rice straw is the most abundant crop by-product in Vietnam, but research on fresh rice straw (FRS) silage is very limited. The objectives of this study were to investigate the effects of ensiling additives and durations on organoleptic characteristics and chemical compositions of FRS silage and to determine the suitable substitution of green grass with FRS silage in growing beef cattle under an intensive production condition. Materials and Methods: In Experiment 1, urea, ammonia and lactic acid microbes were employed to mechanically treat FRS bales. The bales were stored indoor up to 16 weeks in separate bags for organoleptic and chemical assessments at different preservation durations. In experiment 2, the best FRS silage from experiment 1 was used to replace VA06 grass in dietary forage with different dry matter levels: No FRS silage (Control), 1/3 FRS silage and 2/3 FRS silage. Fifteen Laid Sind growing cattle were randomly allocated to and individually fed 1 of 3 forage treatments for 12 weeks, after a 2 week adaptation. Results: The 2% urea treated FRS (fresh matter basis) (URS) displayed the best quality with stably high pH, yellow color and strong ammoniac odor, highest crude protein content throughout 16 week preservation. The replacement of 2/3 URS reduced daily feed intake, but did not cause significant differences in growth performance. Conclusion: These findings suggest that 2% urea is an effective treatment to preserve FRS and URS can replace up to 2/3 green grass in growing beef cattle diets under an intensive production condition.
Don Viet Nguyen and Lam Hoang Dang, 2020. Fresh Rice Straw Silage Affected by Ensiling Additives and Durations and its Utilisation in Beef Cattle Diets. Asian Journal of Animal Sciences, 14: 16-24.