초록
Two experiments were carried out concerning the effects of urea-molasses cake (UMC) and its separate components as supplements on rumen environment, in sacco feed degradability and intake of swamp buffaloes fed rice straw, grasses or a mixture of grasses and rice straw. Experiment 1 was a change-over design with 4 animals and 6 treatments. The buffaloes were fed rice straw ad libitum, and the experimental treatments were: no supplementation (R); 700 g of the complete urea-molasses cake (RUMC); 53.2 g urea (RU); 276 g rice bran and 52.5 coconut meal (RRC); 26.6 g salt, 26.6 g bone meal and 2.1 g trace minerals (RMi); and 25 g molasses (RMo). Experiment 2 was a Latin square design with four diets and four animals. The treatments were: rice straw ad libitum and mixed grass (RG) at 2.5 g dry matter per kg live weight (LW); RG plus 700 g urea-molasses cake (RGUMC); mixed grass ad libitum (G); and G plus 700 g cake (GUMC). In both experiments the supplements were fed once daily. In Exp. 1 although the rumen pH was significantly different (p<0.05) among diets, it varied only from 6.90 to 7.06. The ruminal ammonia was also significantly (p<0.05) different among the diets with RUMC significantly higher than R. Total bacterial and protozoal counts were significantly (p<0.05) higher for the RUMC, RU, RMo and RRC diets. Total feed and rice straw intakes were highest for RUMC (p<0.05) and lowest for the RMi and RMo diets, but in sacco degradability of four different roughages were not significantly different among diets. In Exp. 2, rumen pHs of the diets differed significantly and (p<0.01) ranged from 7.04 - 7.19. Ruminal $NH_3-N$ concentrations (mg/100 ml) were also significantly different (p<0.05), and higher for the RGUMC, G and GUMC diets. The total counts of bacteria and protozoa were significantly (p<0.05) higher for the RGUMC, G and GUMC diets. The total feed intake and roughage intake were significantly (p<0.05) higher for the RGUMC, G and GUMC diets compared to the RG diet. Correspondingly, LW changes also differed among treatments (p=0.06). It was concluded that there were significant increases in rumen $NH_3-N$ concentration, microbial populations and feed intake in the buffaloes by UMC supplementation, whereas the significant difference in in sacco DM degradation was not found by any type of supplementation. There seemed to be a need of a combination of urea, molasses, minerals and other protein nitrogen sources to enhance rice straw intake. Adding grass to the rice straw diet at 0.25% LW (DM) should also be considered to maintain buffalo rumen function and production with UMC supplementation, when rice straw is the main roughage.