Sheep fed forage chicory (Cichorium intybus) or perennial ryegrass (Lolium perenne) have similar methane emissions

Forage chicory (Cichorium intybus) has the potential to mitigate methane emissions from ruminants. It was reported that the reduction can be up to 30% compared with perennial ryegrass (Lolium perenne). To accurately evaluate the reduction, fresh chicory and perennial ryegrass in the vegetative state were fed to 24 wethers, 8 of which rumen-fistulated, at 1.3 and 2.2 times maintenance metabolisable energy requirements. Dry matter (DM) intake, whole tract apparent digestibility, rumen fermentation parameters and rumen liquid passage rate were measured in metabolism crates, and methane emissions determined using a calorimetric technique. Chemical analyses showed that chicory contained less DM, organic matter (OM), crude protein, neutral detergent fibre (aNDF), acid detergent fibre (ADF), cellulose and hemicellulose, but more hot water-soluble carbohydrate and pectin, than perennial ryegrass. Methane yield (g/kg DM intake) of wethers fed chicory did not differ from that of those fed perennial ryegrass. Yield was lower at the high versus the low feeding level of ryegrass. Apparent digestibility of DM and OM was higher, and aNDF, ADF, hemicellulose and cellulose was lower, in wethers fed chicory versus perennial ryegrass. In situ DM degradation rate of chicory was higher than that of perennial ryegrass. Rumen liquid passage rate was the same for wethers fed the two forages and higher at the high feeding level. The reduction in methane emissions by feeding vegetative chicory to wethers was limited, but increased feeding level reduces methane yields per unit of DM intake.