Dry matter intake and methane emissions of beef cattle grazing tall fescue pastures

A two-year study was conducted to use methane (CH₄) production as an indicator of beef cattle efficiency on tall fescue (Festuca arundinacea) pasture management systems and to evaluate the importance of dry matter intake (DMI) among different tall fescue systems At Blount Unit, two steers on two pastures each of endophyte (Neotyphodium coenophialum) infected (E+) tall fescue, of endophyte free (E-) tall fescue, of E+/E-(1:1 ratio), and of E+/clover (Trifolium repens) were used to determine CH₄ and DMI At Holston Unit, four steers and four cow/calf pairs on one pasture each of a best management practices (BMP) pasture system and of an unimproved pasture (UIP) system were used to determine CH₄ and DMI Grazing occurred from March to September in 1997 and 1998. At Blount Unit, steers on E+ pasture gained less (P< 0.05) weight than those on the E- and E+/clover pastures and consumed less (P < 0.05) forage than on all other treatments There were no differences in ADG and DMI, except that cows consumed more (P < 0 05) forage than steers at Holston Unit Animals on the BMP produced less (P< 0.05) CH₄ than the UIP. Cows produced more (P < 0.05) CH₄ than steers The E+/clover and BMP pasture systems were lower (P < 0.05) in ADF and NDF and higher (P < 0 05) in CP and IVDMD than the other pasture systems within their respective unit The presence of clover in E+ tall fescue increased forage quality, DMI,and ADG over that of E+ tall fescue This coupled with other management strategies may reduce CH₄ production.