DIGESTION, RUMEN FERMENTATION AND CHEWING BEHAVIOR OF RED DEER FED FRESH CHICORY AND PERENNIAL RYEGRASS

Pure chicory (Cichorium intybus) and perennial ryegrass (Lolium perenn e) forages were cut and fed fresh at Palmerston North, New Zealand, du ring March 1993 to castrated male red deer kept indoors in metabolism crates. Chicory contained lower levels of dry matter, higher levels of ash, and had a higher ratio of readily fermentable: structural carboh ydrate than perennial ryegrass. Apparent digestibility of organic matt er was highest for chicory (0.81 v. 0.72), but cellulose apparent dige stibility was highest for perennial ryegrass (0.71 v. 0.59). Relative to perennial ryegrass, the rumen fluid of deer fed chicory contained h igher concentrations of protozoa, ammonia and total volatile fatty aci ds (VFA) but had a lower pH at 15.00 h. Chicory-fed deer had higher ru men VFA molar proportions of n-butyrate and a higher acetate:propionat e ratio. Total eating time and chews during feeding/g dry matter intak e were similar for deer fed the two forages, but deer fed chicory spen t much less time ruminating (33 v. 270 min/day) and had fewer ruminati on boluses (38 v. 305/day). It was concluded that the low rumination t ime may indicate rapid disintegration of chicory in the rumen to <1 mm critical particle size, and that particle breakdown and rumen fractio nal outflow rate should be measured in future experiments with deer fe d on chicory.