title: The effect of high dietary cation concentration on methanogenesis by steers fed diets with and without ionophores.
abstract: Nine steers (300 to 350 kg body weight) were divided into three groups and received either no ionophore, monensin or lasalocid in a 70% cracked corn basal diet for the entire experiment. Within each group, a 3 X 3 Latin-square design was used to evaluate the effect of a high cation concentration added to the diets on in vivo methanogenesis. The three cation treatments consisted of NaCl or KCl addition (Na or K increased to 2.5% of diet dry matter) or no cation addition. Sodium addition decreased methane production in the monensin group 19% when compared with control (P less than .05). Sodium also tended to decrease methane in the lasalocid group (P less than .1) but had no effect on the no-ionophore group. There was no significant effect of K addition on methane production when compared to no added cation. However, K tended to increase methane in both the lasalocid and no-ionophore groups and decrease methane in the monensin group. Results of this experiment support in vitro evidence that cation levels may modulate ionophore effects on methane production.
mesh_terms: D000818:Animals; D002417:Cattle / Q000378:metabolism*; D004032:Diet; D005663:Furans / Q000494:pharmacology*; D007476:Ionophores / Q000494:pharmacology*; D007832:Lasalocid / Q000494:pharmacology*; D008297:Male; D008697:Methane / Q000096:biosynthesis*; D008985:Monensin / Q000494:pharmacology*; D011188:Potassium / Q000378:metabolism; D012964:Sodium / Q000378:metabolism
chemical_list: D005663:Furans; D007476:Ionophores; D008985:Monensin; D012964:Sodium; D008697:Methane; D011188:Potassium; D007832:Lasalocid