Ammonia or urea treatments of straw increase the digestibility, improve straw intake
and the growth rate of bulls as compared to untreated straw feeding. The input of one kg
N for straw treatment effects increased body weights between 0.76 and 7.0 kg averaging
3 kg. In the case of lower response N-fertilizing of grain or forage and feeding to beef
cattle or other animals seems to be more efficient as compared to treatment of straw
with N sources. Ammoniation of straw by ammonia and urea seems to be justifiable
only, when
. a high portion of N (more than 40%) is fixed in the straw and available for ruminants
?? digestibility and intake of the straw are considerably increased
- more than 4 kg weight gain per kg added N were achieved (comparable with 20 kg
grain per kg N and a cereal : beef conversion ratio of 5 to 1).
More long term dose-response feeding experiments with ammonia or urea treated
straws are necessary as a precondition for an improved nutritional, energetical and
ecological evaluation of the treatments.