title: Plasma clearance of L- and D-lactate in steers fed alfalfa hay or high concentrate diets.
abstract: Experiments were conducted with 40 steers to evaluate the effects of diet (alfalfa hay vs high concentrate) on the rates of elimination of D- and L-lactate from plasma. Plasma L- and D-lactate clearance rates were determined before (Period I) and 114 d after (Period II) an abrupt switch from the alfalfa hay to the high concentrate diet. One group of steers received the hay diet throughout the experiment. Diet or period did not alter the rate of disappearance of L-lactate from plasma; the half-life was 13.5 to 15.5 min. D-lactate disappearance from plasma followed an exponential decay curve with at least two components; however, diet or period did not alter the calculated rates of disappearance. The half-life of the first component was 9 to 28 min and the second component was 207 min. Characteristics describing D- or L-lactate metabolism were not highly correlated with lactate utilization for fatty acid synthesis. These data demonstrate that, in steers adapted to a high concentrate diet consuming 18.2 Mcal ME X head-1 X d-1, clearance of D(-)- or L(+)-lactate is not different from that in steers fed alfalfa hay consuming 23.1 Mcal ME X head-1 X d-1.
mesh_terms: D000818:Animals; D001835:Body Weight; D004044:Dietary Proteins / Q000378:metabolism; D002149:Energy Intake; D004734:Energy Metabolism; D006207:Half-Life; D006736:Horses / Q000378:metabolism*; D007773:Lactates / Q000097:blood* / Q000378:metabolism; D019344:Lactic Acid; D008297:Male; D000455:Medicago sativa; D013237:Stereoisomerism
chemical_list: D004044:Dietary Proteins; D007773:Lactates; D019344:Lactic Acid