اثر باکتری تولید کننده اسید لاکتیک (LAB) و اوره بر ترکیب شیمیایی و ارزش غذایی علوفه کامل جو

This experiment was carried out to study the effects of Lactic Acid Bacteria (LAB) and urea on chemical composition, nutritive value and rumen fermentation characteristics of whole-crop barley. In a completely randomized design with cross over arrangement, 4 Suffolk male lambs were used. Whole-crop barley was either treated with LAB solution (35% dry matter) at the rate of 2 L/ton herbage fresh weight or urea (55% dry matter) at the rate of 40 Kg/ton dry matter herbage and ensiled for 60 days. Low dry matter silages had lower pH and higher residual water soluble carbohydrates, ammonia-N, lactic acid and ethanol and higher lactate:acetate ratios. LAB resulted in higher lactic acid content and lactate:acetate ratios. DM (P<0.001), OM (P<0.01), NDF (P<0.05), ADF (P<0.01) and total nitrogen (TN) digestibility increased with additives. Mean rumen ammonia-N concentration and pH significantly (P<0.05) increased with urea-treated silages. Rumen propionate concentration was significantly (P<0.01) higher with LAB-treated silages than with urea-treated ones. The results indicated that the addition of LAB at the rate of 2 L/ton fresh weight to whole-crop barley at 35% dry matter enhanced fermentation and nutritive value.