2006 年 49 巻 p. 39-44
The experiment was conducted in northeast of Thailand to examine the nitrogen utilization of Thai native cattle and swamp buffalo fed ruzigrass hay (crude protein 6.7 %) . Four Thai native cattle (average bodyweight (BW) 205 kg) and four swamp buffalo (average BW 353 kg) were housed individually in pen. They were fed with ruzigrass hay at 2 % of BW. Dry matter intake per BW and the apparent digestibility of ruzigrass hay were not different between native cattle and swamp buffalo. Nitrogen intake, fecal nitrogen excretion, and nitrogen retention per BW were not different between native cattle and swamp buffalo. On the other hand, the urinary nitrogen excretion per BW of native cattle was higher than swamp buffalo. The pH, ammonia-nitrogen, total nitrogen and total volatile fatty acid in rumen fluid did not differ between native cattle and swamp buffalo. Hematocrit was higher and concentration of plasma urea nitrogen was lower in native cattle than swamp buffalo.
These results indicated that digestion performance was not different between native cattle and swamp buffalo, but nitrogen utilization in swamp buffalo was better than in native cattle. It was possible that swamp buffalo was superior in utilizing low quality roughage compared with native cattle.
