Different sources of ammonia for improving the nutritive value of low quality roughages

Abstract

The study was undertaken to investigate the effectiveness of anhydrous NH 3, aqueous NH 4OH and urea + urease as sources of ammonia for treating maize stover, rice and wheat straws at graded treatment rates of 0, 25 and 50 g NH 3/kg DM of roughage and at two moisture levels of 20 and 40% in all combinations in improving dry matter digestibility in vitro (IVDMD), organic matter digestibility in vitro (IVOMD) and crude protein (CP) contents when allowed to react for 15 or 30 days. Rate of ammonia was the most important factor in enhancing IVDMD, IVOMD and CP. Moisture level and days of reaction had a less important influence on the parameters measured. While anhydrous NH 3 was most effective in improving IVDMD and IVOMD of maize stover, aqueous NH 4OH had a similar effect in increasing IVDMD and IVOMD of rice and wheat straws and urea + urease was the least effective but promising. Highest responses in IVDMD and IVOMD were obtained with rice straw, followed by wheat straw and, lastly, maize stover. In a second experiment maize stover which was treated with aqueous NH 4OH at 0, 25 and 50 g NH 3/kg DM at two moisture levels of 20 and 40% was given to Black Headed Persian rams. Digestibility of DM and OM and voluntary feed intake were improved significantly ( P < 0.01) by ammonia treatment and there was also a significant ( P < 0.01) response to increasing moisture levels.