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Various chemical compounds might be added to forage to maintain or improve the quality value of a crop ensiled. The aim of the present experiment was to evaluate the fermentation characteristics, in situ rumen degradation and Aerobic Stability of whole crop barley ensiled with Urea or aqueous Ammonia. In the first experiment, Whole crop barley was harvested (35% DM), chopped, and then ensiled using laboratory silos (n= 4) as untreated (UT) or treated with urea (10, 20, 30 and 40 g kg-1 DM; U1, U2, U3 and U4, respectively) or aqueousammonia (10 and 20 g kg-1 DM; A1 and A2, respectively) for 30 days. Standard procedures were used to determine the chemical composition of the samples. The pH of the aqueous silage extract was determined using a pH meter. Ammonia-N concentration was determined in acidified silage extract (5 ml of the extract + 5 ml of 0.2 M HCl) using a distillation method. Four sheep (live weight: 44±3 kg) fitted with rumen fistulae were used. Approximately 5 g DM of each sample was placed in a polyester nylon cloth bag (10 × 12 cm, pore size of 52 μm, n=4), then incubated in the rumen for 0.0, 2, 4, 8, 16, 24, 48, 72 and 96 h. Rumen removal bags were washed in cold running water and dried in oven (60 °C, 48 h), then weighted to determine DM disappearance. The equation of P= a+b (1-e-ct) was applied to determine the coefficients (a= quickly degradable fraction, b= slowly degradable fraction, c= fractional degradation rate constant). Both urea and anhydrous ammonia caused a significant (P |
