Techniques for trapping ammonia generated from urea treatment of barley straw

Three step-wise experiments were conducted to determine the ability of feeds in trapping excess ammonia from urea treated barley straw. In the first experiment, shredded barley straw was treated with urea (60 g kg−1 DM) at 300 and 400 g moisture kg−1 in laboratory silos. They were stored in incubator at 26 °C for 7, 14, 21 and 28 days. This was used to estimate the extent of urea hydrolysis and nitrogen retention. The second experiment measured the outflow rate of ammonia by blowing in air through treated straw into dilute H2SO4. The third experiment assessed the ability of grass and citrus pulp silages in holding ammonia. ydrolysis was extensive (90–100%) but independent of moisture and treatment period (P > 0.05). About 74% of nitrogen added in the form of urea in treated straw was lost during aeration. Fermentation enhanced the ammonia holding capacity of citrus pulp. This was further improved with time and addition of molasses. Itʹs nitrogen content was increased from 11.7 to 21.2 g kg−1 DM. This decreased to 16.0 g kg−1 DM about 5 h after gassing. ement in the nitrogen content of feeds with gassing suggest that dry matter and nitrogen intake by ruminants can be enhanced.