A study on the effect of frequency of urea ingestion on the utilization of low quality roughage by steers

Abstract

Steers were fed a low quality roughage supplemented with 50 g urea day-1 administered at different frequencies. The effect of the different treatments was measured in terms of intake, digestibility, nitrogen balance and changes of some rumen fermentation measures in two different but complementary experiments. Utilization of the roughage was enhanced as the frequency of ingestion of urea increased. Organic matter digestibility was unaffected but voluntary intake was stimulated by all urea treatments. There was negative nitrogen balance in control animals but all treated were in positive nitrogen balance. However, the greatest retention was produced when urea was sprayed onto the ration. Possible reasons for the better utilization of urea as the frequency of ingestion spreads over the day are suggested by the results observed in the fermentation measures considered.