Effect of urea as non-protein nitrogenous substance on the rumen microbial ecosystem in fattening suakin lambs

Twelve apparently healthy weaned male Suakin lambs were subjected to this study. The lambs were allotted randomly into four groups (3 lambs/each) fed on control diet, experimental diets supplemented with 0.5%, 1.0% and 1.5% urea, respectively. The results revealed obvious changes in the smell and consistency of ruminal fluid in lambs with increased levels of urea in diet. Also there is slight changes in the protozoal activity and color of ruminal fluid between the treatment groups. The results revealed that pH of ruminal fluid is changed gradually from (6.61 ± 0.08) in Group-1 to (7.08 ± 0.07, 7.16 ± 0.08and 7.22 ± 0.08) in lambs of Groups-1, Group-2 and Group-3. The time required for methylene blue reduction (6.11±0.27 and 6.17 ± 0.23) and sedimentation & floatation (23.67 ± 1.03 and 23.56 ± 0.71) showed significant increase in lambs supplemented with 1.0% and 1.5% urea.

The obtained results revealed significant reductions in the total protozoal count (624.44x10³ ± 6.48, 629.44 x10³ ± 7.09 and 617.78 x10³ ± 9.83) and percentage of holotrichs species (55.67 x103 ± 2.85, 66.78 x10³ ± 1.67 and 47.56 x10³ ± 3.44) in lambs fed on experimental diet supplemented with urea. Meanwhile the percentage and count of entodiniomorphs species (568.78 x10³ ± 7.32, 563.78 x10³ ± 7.77 and 570.22 x10³ ± 3.75) showed significant increase in those lambs fed experimental diet supplemented with urea.