Altering the particle size of supplemental zeolite (clinoptilolite): effects on nitrogen utilization and nutrient digestibility in backgrounding cattle

摘要

The indiscriminate breakdown of dietary nitrogen (N) by the ruminal microbes, and subsequent loss of ammonia-N (NH3-N) from the rumen into blood, is the primary reason for the capture of only 10% to 20% of feed N into meat protein in beef cattle, with the remainder (80% to 90%) excreted as urine and fecal N (Satter et al., 2002). Because it is more environmentally labile than fecal N, excreted urine N, primarily urea-N (UUN), contributes to reactive N emissions (e.g., NH3-N) that compromise ecological health. Thus, limiting UUN excretion has the potential to reduce the environmental cost of beef production.