Disadvantages of Urea Utilization for Ruminants:
The amount of urea can be used in diets is rather limited due to their rapid hydrolysis to NH3-N in the
rumen by microbial enzymes (Golombeski et al., 2006; Highstreet et al., 2010). This rapid breakdown to NH3-
N can occur at a much faster rate than NH3-N utilization by the rumen bacteria, resulting in accumulation and
escape of NH3-N from the rumen. The net result is that a potentially large part of the N from NPN sources
is excreted in the urine and can contribute to environmental pollution (Broderick et al., 2009; Inostroza et al.,
2010).