Comparison of alfalfa, birdsfoot trefoil, and cicer milkvetch in combination with 25, 50, or 75% tall fescue in a continuous-culture system

Abstract

ABSTRACT A continuous-culture experiment was performed to investigate the effects of tall fescue (TF)-to-legume ratios (TF:legume = 75:25, 50:50, or 25:75 on a DM basis) of 3 different TF-legume mixed diets [TF-alfalfa (TF+AF), TF-birdsfoot trefoil (TF+BT), or TF-cicer milkvetch (TF+CM)] on in vitro fermentation characteristics. Nine dietary treatments were tested in a 3 (TF-legume ratio) × 3 (TF-legume mixed diet) split-plot design. Dietary treatments did not affect the concentrations of total VFA, acetate, and butyrate, whereas increasing legume proportion increased propionate concentration (P = 0.03). Regardless of TF-legume ratio, feeding TF+CM re sulted in the greatest propionate concentration, whereas TF+AF and TF+BT maintained a similar concentration of propionate. The TF+AF combination resulted in a greater acetate-to-propionate ratio than TF+BT or TF+CM (P = 0.03). Decrease in ammonia-N concentration (P