Ad Libitum Intake and Digestibility of Selected Reed Canarygrass (Phalaris Arundinacea L.) Clones as Measured by the Fecal Index Method

Significant positive correlations (+0.92 to 0.97) were obtained between fecal nitrogen and digestible organic matter (D.O.M.) when forages, at varying stages of maturity, were fed to lambs in indoor digestion stalls. Forages used were alfalfa (Vernal), acceptable clones (6889—2 and 6017—0) and unacceptable clones (6332—1 and 6049—1) of reed canarygrass. A separate regression equation was computed for alfalfa, clone 6889—2 and clone 6017—0 and for clone 6049—1 and clone 6332—1. The regression equations obtained from the indoor digestion trials were used to compute D.O.M. from ad libitumgrazing trials with lambs. A significant difference (P<.05) in D.O.M. between acceptability groups of reed canarygrass was detected in only the second regrowth of 1963. Differences (P<.25 and <.01) in organic matter intake (O.M.I.) between acceptability groups were obtained for the initial-growth and first regrowth forages in 1962. Differences (P<.01 and <.10) were found in the first and second regrowth in 1963. The O.M.I, of the acceptable clones was greater than the unacceptable clones in all the grazing experiments.