Adaptation effects of ionophoreso n rumen fermentation

The effect of monensin on the in vitro degradation of cellulosewas investigated using ruminal fluid obtained from sheep adapted and unadapted to the antibiotic. /n ylyo ruminal adaptation to monensin was also examined over a six-week treatment period. Results showed that monensin severely inhibited total VFA production when cellulose was offered as substrate to unadapted ruminal organisms. There was only a small decrease when the rumen inoculum was obtained from sheep fed monensin for 32 days. Addition of monensin to the diet resulted in higher propionate and lower butyrate concentrations when compared with values obtained from'sheep fed diets without monensin. The addition of monensin decreased dilution rate and increased rumen volume.Die uitwerking van monensin op die in vitro afbraak van sellulose is ondersoekd eur gebruikt e maak van rumenvloeistowf at verkry is van skapew at aangepase n nie aangepasi s nie.l n vivog rootpensaanpassing by monensin is ook ondersoek tydens 'n ses-weke behandelingstydperkR. esultateh et getoond at monensind ie totale produksie van vlugtige vetsure ernstig onderdruk het wanneer sellulose as substraat by onaangepaste grootpensorganismes gebruiki s. Daarw as slegs' n kleinv erlagingw anneere ntmateriaal van die grootpens van skape verkry is wat 32 dae monensin gevoer is. Byvoeging van monensin by die rantsoen het ho€r propionaat en laerb utiraatkonsentrasietso t gevolg,i n vergelykingm et waardes verkry van skape wat nie monensin gevoer is nie. Byvoeging van monensinv erlaagv erdunningstempoe n verhoogg rootpensv olume. Keywords: Monensin, rumen fermentation, volatile fatty acids, cell ulose degradation,a daptatio