02286naa a2200265 a 450000100080000000500110000800800410001902400280006010000140008824501930010226000090029552014360030465000100174065000110175065000200176165000100178165300240179165300170181565300260183265300230185865300190188170000240190070000200192477300760194420548242016-10-20       1983    bl uuuu     u00u1 u    #d7 a10.4141/cjas83-0462DOI1 aSOOFI, R.  aRate and extent of digestion of cotton thread and of dry matter and cell wall constituents of soybean stover, alfalfa and their blends and rumen characteristics of sheep fed these forages.  c1983  aThe rate and extent of digestion of cell wall fractions of soybean stover (SBS), alfalfa (ALF) and mixtures of these forages and the interactions (associative effects) between their components were measured using dacron bags in situ in eight mature sheep. The rate and extent of digestion of cotton thread was also compared to that of cellulose in intact plant cell walls. The extent of dry matter digestibility (DMD) of SBS, 2 SBS:1 ALF, 1 SBS:2 ALF and ALF was 48.1, 56.5, 66.8 and 73.3%, respectively. Neutral detergent fiber (NDF), acid detergent fiber (ADF) and cellulose digestibilities for the 2 SBS:1 ALF blend were 4.2, 4.1 and 4.3 percentage units lower, respectively, than expected values. Observed digestibilities for various components of the 1 SBS:2 ALF blend were not statistically different from expected values. Cotton fiber digestion in the rumen of sheep fed all ALF diets neared completion in 48 8194;h (94.3%) and this value was significantly higher than those for sheep fed SBS (65.0%), 2 SBS:1 ALF (77.0%), and 1 SBS:2 ALF (88.5%). Rumen pH values, after feeding, tended to decline fastest in sheep fed ALF. Nitrogen recycling into the rumen occurred on all diets but was greater as quality of forage decreased. Molar concentrations of volatile fatty acids (VFA) increased after feeding in all instances. Key words: Sheep, soybean stover, alfalfa, associative effects, in situ dacron bag, cellulose digestion  aSheep  aAlfafa  aMedicago Sativa  aOvino  aAssociative effects  aCellulolysis  aDigestão da celulose  aIn situ dacron bag  aSoybean stover1 aFAHEY JUNIOR, G. C.1 a. BERGER, L. L.  tCanadian Journal of Animal Sciencegv. 62, n. 2, p. 373-380, Jun. 1983.