There was a clear difference in NEFA and BUN contents in the blood serum between Brahman cattle and
swamp buffalo. Although there was no report on the difference in NEFA content between these species, Norton
et al.17 reported that plasma urea concentration was
higher in water buffalo than cattle, and suggested higher
renal resorption of urea in water buffalo. Homma7
reported that ammonia nitrogen in rumen fluid was
higher in swamp buffalo than in Holstein cattle when
both animals were given Thimothy hay ad libitum. He
suggested that this was related to a higher nitrogen content in saliva of swamp buffalo and to their ability to concentrate rumen fluid by a higher ability to absorb water
from rumen. In the present study, an increase in BUN
content in blood serum during fasting in comparison with
during feeding was more in swamp buffalo than in Brahman cattle. On the other hand, an increase in NEFA content in blood serum during fasting in comparison with
during feeding was more in Brahman cattle than in
swamp buffalo. It would suggest that, while more energy
was mobilized from body tissue protein in swamp buffalo
during fasting, more energy was mobilized from fat in
Brahman cattle. This might suggest a specific difference
between swamp buffalo and Brahman cattle in energy
mobilization during fasting.
Urinary excretion of allantoin is considered to be a
marker of microbial production in rumen. It tended to be
lower in swamp buffalo than in Brahman cattle, although
it was not statistically significant. This may suggest the
difference of production in microorganisms in rumen
between the two species. However, Samaraweera et al.19
suggested that the endogenous purine derivative excretion is low in buffaloes.
Swamp buffaloes may have an ability to utilize fiber
and energy better than cattle. However, it still requires
further studies to clarify the difference. There are clear
physiological differences, which were clarified when
they were fasted in the present study. The characterization of digestion physiology in swamp buffaloes would
contribute to the establishment of a strategy for sustainable development of local feeding management.